[ { "number": 1, "symbol": "H", "name": "Hydrogen", "period": 1, "group": 1, "col": 1, "row": 1, "family": "Nonmetal", "en": 2.2, "radius": 120.0, "ie": 13.598434599702, "ieStatus": "Predicted (theory)", "ieRaw": "13.598434599702", "ieUncertainty": "0.000000000012", "ieReference": "HDEL", "config": "1s", "shells": [ 1 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Gas", "icon": "⚡", "kind": "Element", "use": "Hydrogen gas is used in some fuel cells to make electricity.", "why": "The lightest element helps connect chemistry, water and clean-energy research." }, { "number": 2, "symbol": "He", "name": "Helium", "period": 1, "group": 18, "col": 18, "row": 1, "family": "Noble gas", "en": null, "radius": 140.0, "ie": 24.587389011, "ieStatus": "Measured / evaluated", "ieRaw": "24.587389011", "ieUncertainty": "0.000000025", "ieReference": "L17714", "config": "1s2", "shells": [ 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Gas", "icon": "❄", "kind": "Element", "use": "Liquid helium cools superconducting magnets in many MRI scanners.", "why": "It stays liquid at extremely low temperatures and hardly reacts." }, { "number": 3, "symbol": "Li", "name": "Lithium", "period": 2, "group": 1, "col": 1, "row": 2, "family": "Alkali metal", "en": 0.98, "radius": 182.0, "ie": 5.391714996, "ieStatus": "Measured / evaluated", "ieRaw": "5.391714996", "ieUncertainty": "0.000000022", "ieReference": "L12261", "config": "1s2.2s", "shells": [ 2, 1 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▣", "kind": "Compounds / ions", "use": "Lithium ions move between electrodes in rechargeable phone and battery-storage cells.", "why": "Its light atoms help batteries store useful energy for their mass." }, { "number": 4, "symbol": "Be", "name": "Beryllium", "period": 2, "group": 2, "col": 2, "row": 2, "family": "Alkaline earth metal", "en": 1.57, "radius": 153.0, "ie": 9.322699, "ieStatus": "Measured / evaluated", "ieRaw": "9.322699", "ieUncertainty": "0.000007", "ieReference": "L5964", "config": "1s2.2s2", "shells": [ 2, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▤", "kind": "Element / alloys", "use": "Beryllium is used in specialised X-ray windows and light, stiff aerospace parts.", "why": "Its low mass and stiffness are useful, but its dust is highly toxic." }, { "number": 5, "symbol": "B", "name": "Boron", "period": 2, "group": 13, "col": 13, "row": 2, "family": "Metalloid", "en": 2.04, "radius": 192.0, "ie": 8.298019, "ieStatus": "Measured / evaluated", "ieRaw": "8.298019", "ieUncertainty": "0.000003", "ieReference": "L12312", "config": "1s2.2s2.2p", "shells": [ 2, 3 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▥", "kind": "Compounds", "use": "Boron compounds help make heat-resistant borosilicate laboratory glass.", "why": "Changing the ingredients of glass changes what it can withstand." }, { "number": 6, "symbol": "C", "name": "Carbon", "period": 2, "group": 14, "col": 14, "row": 2, "family": "Nonmetal", "en": 2.55, "radius": 170.0, "ie": 11.260288, "ieStatus": "Measured / evaluated", "ieRaw": "11.2602880", "ieUncertainty": "0.0000011", "ieReference": "L20057", "config": "1s2.2s2.2p2", "shells": [ 2, 4 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "✎", "kind": "Element", "use": "Graphite, a form of carbon, is used in pencil cores and battery electrodes.", "why": "One element can form very different materials, including graphite and diamond." }, { "number": 7, "symbol": "N", "name": "Nitrogen", "period": 2, "group": 15, "col": 15, "row": 2, "family": "Nonmetal", "en": 3.04, "radius": 155.0, "ie": 14.53413, "ieStatus": "Measured / evaluated", "ieRaw": "14.53413", "ieUncertainty": "0.00004", "ieReference": "L1411", "config": "1s2.2s2.2p3", "shells": [ 2, 5 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Gas", "icon": "❄", "kind": "Element", "use": "Liquid nitrogen is used for rapid cooling; nitrogen gas protects food from oxygen.", "why": "Nitrogen is also part of proteins, but plants usually take it up in compounds." }, { "number": 8, "symbol": "O", "name": "Oxygen", "period": 2, "group": 16, "col": 16, "row": 2, "family": "Nonmetal", "en": 3.44, "radius": 152.0, "ie": 13.618055, "ieStatus": "Measured / evaluated", "ieRaw": "13.618055", "ieUncertainty": "0.000007", "ieReference": "L74,L3760", "config": "1s2.2s2.2p4", "shells": [ 2, 6 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Gas", "icon": "＋", "kind": "Element", "use": "Oxygen gas is supplied for medical breathing support.", "why": "It supports cellular respiration and combustion; these are chemical reactions." }, { "number": 9, "symbol": "F", "name": "Fluorine", "period": 2, "group": 17, "col": 17, "row": 2, "family": "Halogen", "en": 3.98, "radius": 135.0, "ie": 17.42282, "ieStatus": "Measured / evaluated", "ieRaw": "17.42282", "ieUncertainty": "0.00005", "ieReference": "L7481,L526", "config": "1s2.2s2.2p5", "shells": [ 2, 7 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Gas", "icon": "▱", "kind": "Compounds", "use": "Fluoride compounds in toothpaste help protect teeth.", "why": "Fluoride compounds have very different properties from reactive fluorine gas." }, { "number": 10, "symbol": "Ne", "name": "Neon", "period": 2, "group": 18, "col": 18, "row": 2, "family": "Noble gas", "en": null, "radius": 154.0, "ie": 21.564541, "ieStatus": "Measured / evaluated", "ieRaw": "21.564541", "ieUncertainty": "0.000007", "ieReference": "L8826,L1407", "config": "1s2.2s2.2p6", "shells": [ 2, 8 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Gas", "icon": "☷", "kind": "Element", "use": "Neon gas makes the orange-red light in traditional neon signs.", "why": "Electricity can make gas atoms emit characteristic colours of light." }, { "number": 11, "symbol": "Na", "name": "Sodium", "period": 3, "group": 1, "col": 1, "row": 3, "family": "Alkali metal", "en": 0.93, "radius": 227.0, "ie": 5.13907696, "ieStatus": "Measured / evaluated", "ieRaw": "5.13907696", "ieUncertainty": "0.00000025", "ieReference": "L10921,L9648", "config": "[Ne].3s", "shells": [ 2, 8, 1 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "♧", "kind": "Compounds", "use": "Sodium chloride is table salt; sodium compounds have many industrial uses.", "why": "Reactive sodium metal is very different from sodium ions in salt." }, { "number": 12, "symbol": "Mg", "name": "Magnesium", "period": 3, "group": 2, "col": 2, "row": 3, "family": "Alkaline earth metal", "en": 1.31, "radius": 173.0, "ie": 7.646236, "ieStatus": "Measured / evaluated", "ieRaw": "7.646236", "ieUncertainty": "0.000004", "ieReference": "L10635,L6969", "config": "[Ne].3s2", "shells": [ 2, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "✦", "kind": "Element / alloys", "use": "Magnesium is used in light alloys and produces bright light in flares.", "why": "Low density matters when engineers want lighter components." }, { "number": 13, "symbol": "Al", "name": "Aluminium", "period": 3, "group": 13, "col": 13, "row": 3, "family": "Post-transition metal", "en": 1.61, "radius": 184.0, "ie": 5.985769, "ieStatus": "Measured / evaluated", "ieRaw": "5.985769", "ieUncertainty": "0.000003", "ieReference": "L7215,L10321", "config": "[Ne].3s2.3p", "shells": [ 2, 8, 3 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▱", "kind": "Element / alloys", "use": "Aluminium is used in drink cans, aircraft structures and power conductors.", "why": "A thin oxide layer helps protect this light metal from further corrosion." }, { "number": 14, "symbol": "Si", "name": "Silicon", "period": 3, "group": 14, "col": 14, "row": 3, "family": "Metalloid", "en": 1.9, "radius": 210.0, "ie": 8.15168, "ieStatus": "Measured / evaluated", "ieRaw": "8.15168", "ieUncertainty": "0.00003", "ieReference": "L5815", "config": "[Ne].3s2.3p2", "shells": [ 2, 8, 4 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▦", "kind": "Element", "use": "High-purity silicon is used in computer chips and most solar cells.", "why": "Its electrical behaviour can be controlled to make semiconductor devices." }, { "number": 15, "symbol": "P", "name": "Phosphorus", "period": 3, "group": 15, "col": 15, "row": 3, "family": "Nonmetal", "en": 2.19, "radius": 180.0, "ie": 10.486686, "ieStatus": "Measured / evaluated", "ieRaw": "10.486686", "ieUncertainty": "0.000015", "ieReference": "L5148", "config": "[Ne].3s2.3p3", "shells": [ 2, 8, 5 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "♧", "kind": "Compounds", "use": "Phosphate compounds are used in fertilisers.", "why": "Phosphorus is also part of DNA and the molecules cells use to transfer energy." }, { "number": 16, "symbol": "S", "name": "Sulfur", "period": 3, "group": 16, "col": 16, "row": 3, "family": "Nonmetal", "en": 2.58, "radius": 180.0, "ie": 10.3600167, "ieStatus": "Measured / evaluated", "ieRaw": "10.3600167", "ieUncertainty": "0.0000014", "ieReference": "L23116", "config": "[Ne].3s2.3p4", "shells": [ 2, 8, 6 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Compounds", "use": "Sulfur is used to make sulfuric acid, a major industrial chemical.", "why": "Its chemistry connects fertilisers, batteries and mineral processing." }, { "number": 17, "symbol": "Cl", "name": "Chlorine", "period": 3, "group": 17, "col": 17, "row": 3, "family": "Halogen", "en": 3.16, "radius": 175.0, "ie": 12.967633, "ieStatus": "Measured / evaluated", "ieRaw": "12.967633", "ieUncertainty": "0.000016", "ieReference": "L19191", "config": "[Ne].3s2.3p5", "shells": [ 2, 8, 7 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Gas", "icon": "≈", "kind": "Element / compounds", "use": "Chlorine and chlorine-releasing compounds are used to disinfect water.", "why": "Useful treatment depends on controlled dosing; chlorine gas is hazardous." }, { "number": 18, "symbol": "Ar", "name": "Argon", "period": 3, "group": 18, "col": 18, "row": 3, "family": "Noble gas", "en": null, "radius": 188.0, "ie": 15.7596119, "ieStatus": "Measured / evaluated", "ieRaw": "15.7596119", "ieUncertainty": "0.0000005", "ieReference": "L9217", "config": "[Ne].3s2.3p6", "shells": [ 2, 8, 8 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Gas", "icon": "⌁", "kind": "Element", "use": "Argon gas shields hot metal from air during welding.", "why": "Low reactivity makes it a useful protective atmosphere." }, { "number": 19, "symbol": "K", "name": "Potassium", "period": 4, "group": 1, "col": 1, "row": 4, "family": "Alkali metal", "en": 0.82, "radius": 275.0, "ie": 4.34066373, "ieStatus": "Measured / evaluated", "ieRaw": "4.34066373", "ieUncertainty": "0.00000009", "ieReference": "L5451,L5783,L7185", "config": "[Ar].4s", "shells": [ 2, 8, 8, 1 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "♧", "kind": "Compounds", "use": "Potassium compounds are major ingredients of many fertilisers.", "why": "Potassium ions also help nerves and muscles function." }, { "number": 20, "symbol": "Ca", "name": "Calcium", "period": 4, "group": 2, "col": 2, "row": 4, "family": "Alkaline earth metal", "en": 1.0, "radius": 231.0, "ie": 6.113154921, "ieStatus": "Measured / evaluated", "ieRaw": "6.1131549210", "ieUncertainty": "0.0000000005", "ieReference": "L22848", "config": "[Ar].4s2", "shells": [ 2, 8, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▰", "kind": "Compounds", "use": "Calcium compounds are used in cement, plaster and lime.", "why": "Bones contain calcium compounds, not pieces of calcium metal." }, { "number": 21, "symbol": "Sc", "name": "Scandium", "period": 4, "group": 3, "col": 3, "row": 4, "family": "Transition metal", "en": 1.36, "radius": 211.0, "ie": 6.56149, "ieStatus": "Measured / evaluated", "ieRaw": "6.56149", "ieUncertainty": "0.00006", "ieReference": "L7185,L2110", "config": "[Ar].3d.4s2", "shells": [ 2, 8, 9, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "✈", "kind": "Alloys", "use": "Small amounts of scandium strengthen some specialised aluminium alloys.", "why": "A tiny alloying addition can change how a material performs." }, { "number": 22, "symbol": "Ti", "name": "Titanium", "period": 4, "group": 4, "col": 4, "row": 4, "family": "Transition metal", "en": 1.54, "radius": 187.0, "ie": 6.82812, "ieStatus": "Measured / evaluated", "ieRaw": "6.828120", "ieUncertainty": "0.000012", "ieReference": "L17996", "config": "[Ar].3d2.4s2", "shells": [ 2, 8, 10, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "✈", "kind": "Element / alloys", "use": "Titanium alloys are used in aircraft and medical implants.", "why": "Strength, low density and corrosion resistance make a useful combination." }, { "number": 23, "symbol": "V", "name": "Vanadium", "period": 4, "group": 5, "col": 5, "row": 4, "family": "Transition metal", "en": 1.63, "radius": 179.0, "ie": 6.746187, "ieStatus": "Measured / evaluated", "ieRaw": "6.746187", "ieUncertainty": "0.000021", "ieReference": "L17712,L20010", "config": "[Ar].3d3.4s2", "shells": [ 2, 8, 11, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▣", "kind": "Compounds / ions", "use": "Vanadium ions store energy in vanadium redox-flow batteries.", "why": "The ability to change oxidation state supports energy storage." }, { "number": 24, "symbol": "Cr", "name": "Chromium", "period": 4, "group": 6, "col": 6, "row": 4, "family": "Transition metal", "en": 1.66, "radius": 189.0, "ie": 6.76651, "ieStatus": "Measured / evaluated", "ieRaw": "6.76651", "ieUncertainty": "0.00004", "ieReference": "L7185,L2832", "config": "[Ar].3d5.4s", "shells": [ 2, 8, 13, 1 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▰", "kind": "Alloys", "use": "Chromium helps give stainless steel its corrosion resistance.", "why": "A protective chromium-rich surface layer helps steel last." }, { "number": 25, "symbol": "Mn", "name": "Manganese", "period": 4, "group": 7, "col": 7, "row": 4, "family": "Transition metal", "en": 1.55, "radius": 197.0, "ie": 7.434038, "ieStatus": "Measured / evaluated", "ieRaw": "7.4340380", "ieUncertainty": "0.0000012", "ieReference": "L19057", "config": "[Ar].3d5.4s2", "shells": [ 2, 8, 13, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▣", "kind": "Compounds / alloys", "use": "Manganese dioxide is used in alkaline batteries; manganese is also used in steel.", "why": "The same element can serve different roles in compounds and alloys." }, { "number": 26, "symbol": "Fe", "name": "Iron", "period": 4, "group": 8, "col": 8, "row": 4, "family": "Transition metal", "en": 1.83, "radius": 194.0, "ie": 7.9024681, "ieStatus": "Measured / evaluated", "ieRaw": "7.9024681", "ieUncertainty": "0.0000012", "ieReference": "L7743c109", "config": "[Ar].3d6.4s2", "shells": [ 2, 8, 14, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▰", "kind": "Alloys", "use": "Iron is the main element in steel used for buildings, tools and machines.", "why": "Its alloys combine useful strength, availability and cost." }, { "number": 27, "symbol": "Co", "name": "Cobalt", "period": 4, "group": 9, "col": 9, "row": 4, "family": "Transition metal", "en": 1.88, "radius": 192.0, "ie": 7.88101, "ieStatus": "Measured / evaluated", "ieRaw": "7.88101", "ieUncertainty": "0.00012", "ieReference": "L10545", "config": "[Ar].3d7.4s2", "shells": [ 2, 8, 15, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▣", "kind": "Compounds / alloys", "use": "Cobalt compounds are used in some rechargeable battery cathodes.", "why": "Its chemistry also helps make heat-resistant alloys and strong magnets." }, { "number": 28, "symbol": "Ni", "name": "Nickel", "period": 4, "group": 10, "col": 10, "row": 4, "family": "Transition metal", "en": 1.91, "radius": 163.0, "ie": 7.639878, "ieStatus": "Measured / evaluated", "ieRaw": "7.639878", "ieUncertainty": "0.000017", "ieReference": "L12369", "config": "[Ar].3d8.4s2", "shells": [ 2, 8, 16, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▣", "kind": "Alloys / compounds", "use": "Nickel is used in stainless steel and in some battery materials.", "why": "It supports corrosion resistance and several energy-storage chemistries." }, { "number": 29, "symbol": "Cu", "name": "Copper", "period": 4, "group": 11, "col": 11, "row": 4, "family": "Transition metal", "en": 1.9, "radius": 140.0, "ie": 7.72638, "ieStatus": "Measured / evaluated", "ieRaw": "7.726380", "ieUncertainty": "0.000004", "ieReference": "L14897", "config": "[Ar].3d10.4s", "shells": [ 2, 8, 18, 1 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⌁", "kind": "Element", "use": "Copper is used in electrical wiring and heat exchangers.", "why": "It carries electricity and heat very well." }, { "number": 30, "symbol": "Zn", "name": "Zinc", "period": 4, "group": 12, "col": 12, "row": 4, "family": "Transition metal", "en": 1.65, "radius": 139.0, "ie": 9.394197, "ieStatus": "Measured / evaluated", "ieRaw": "9.394197", "ieUncertainty": "0.000006", "ieReference": "L13951", "config": "[Ar].3d10.4s2", "shells": [ 2, 8, 18, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▰", "kind": "Element", "use": "Zinc coats steel in galvanising to help prevent rust.", "why": "The coating can protect steel even at small scratches." }, { "number": 31, "symbol": "Ga", "name": "Gallium", "period": 4, "group": 13, "col": 13, "row": 4, "family": "Post-transition metal", "en": 1.81, "radius": 187.0, "ie": 5.999302, "ieStatus": "Measured / evaluated", "ieRaw": "5.9993020", "ieUncertainty": "0.0000012", "ieReference": "L5566", "config": "[Ar].3d10.4s2.4p", "shells": [ 2, 8, 18, 3 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▦", "kind": "Compounds", "use": "Gallium nitride is used in efficient power electronics and LEDs.", "why": "A compound semiconductor can behave very differently from a metal." }, { "number": 32, "symbol": "Ge", "name": "Germanium", "period": 4, "group": 14, "col": 14, "row": 4, "family": "Metalloid", "en": 2.01, "radius": 211.0, "ie": 7.899435, "ieStatus": "Measured / evaluated", "ieRaw": "7.899435", "ieUncertainty": "0.000012", "ieReference": "L3935,L12369", "config": "[Ar].3d10.4s2.4p2", "shells": [ 2, 8, 18, 4 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▦", "kind": "Element / compounds", "use": "Germanium is used in infrared optics and some optical-fibre materials.", "why": "Its interaction with light supports communication and sensing." }, { "number": 33, "symbol": "As", "name": "Arsenic", "period": 4, "group": 15, "col": 15, "row": 4, "family": "Metalloid", "en": 2.18, "radius": 185.0, "ie": 9.78855, "ieStatus": "Measured / evaluated", "ieRaw": "9.78855", "ieUncertainty": "0.00025", "ieReference": "L1351", "config": "[Ar].3d10.4s2.4p3", "shells": [ 2, 8, 18, 5 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▦", "kind": "Compounds", "use": "Gallium arsenide is used in some specialised semiconductor devices.", "why": "Arsenic chemistry has useful roles, but many arsenic compounds are toxic." }, { "number": 34, "symbol": "Se", "name": "Selenium", "period": 4, "group": 16, "col": 16, "row": 4, "family": "Nonmetal", "en": 2.55, "radius": 190.0, "ie": 9.752368, "ieStatus": "Measured / evaluated", "ieRaw": "9.752368", "ieUncertainty": "0.000006", "ieReference": "L21645", "config": "[Ar].3d10.4s2.4p4", "shells": [ 2, 8, 18, 6 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▦", "kind": "Element", "use": "Selenium is used in some photoconductors and glass-making processes.", "why": "Its response to light helped develop imaging technology." }, { "number": 35, "symbol": "Br", "name": "Bromine", "period": 4, "group": 17, "col": 17, "row": 4, "family": "Halogen", "en": 2.96, "radius": 183.0, "ie": 11.81381, "ieStatus": "Measured / evaluated", "ieRaw": "11.81381", "ieUncertainty": "0.00006", "ieReference": "L351,L67", "config": "[Ar].3d10.4s2.4p5", "shells": [ 2, 8, 18, 7 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Liquid", "icon": "▱", "kind": "Compounds", "use": "Bromine compounds are used in some flame-retardant materials.", "why": "Compound design can change how materials behave in a fire." }, { "number": 36, "symbol": "Kr", "name": "Krypton", "period": 4, "group": 18, "col": 18, "row": 4, "family": "Noble gas", "en": 3.0, "radius": 202.0, "ie": 13.9996055, "ieStatus": "Measured / evaluated", "ieRaw": "13.9996055", "ieUncertainty": "0.0000020", "ieReference": "L12196", "config": "[Ar].3d10.4s2.4p6", "shells": [ 2, 8, 18, 8 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Gas", "icon": "☷", "kind": "Element", "use": "Krypton is used in some lamps and insulated glazing.", "why": "A less reactive gas can provide useful optical and thermal properties." }, { "number": 37, "symbol": "Rb", "name": "Rubidium", "period": 5, "group": 1, "col": 1, "row": 5, "family": "Alkali metal", "en": 0.82, "radius": 303.0, "ie": 4.1771281, "ieStatus": "Measured / evaluated", "ieRaw": "4.1771281", "ieUncertainty": "0.0000012", "ieReference": "L4740,L5783", "config": "[Kr].5s", "shells": [ 2, 8, 18, 8, 1 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "◷", "kind": "Element / isotope", "use": "Rubidium atoms provide a frequency reference in some atomic clocks.", "why": "Atomic energy differences can be used to keep very accurate time." }, { "number": 38, "symbol": "Sr", "name": "Strontium", "period": 5, "group": 2, "col": 2, "row": 5, "family": "Alkaline earth metal", "en": 0.95, "radius": 249.0, "ie": 5.69486745, "ieStatus": "Measured / evaluated", "ieRaw": "5.69486745", "ieUncertainty": "0.00000012", "ieReference": "L15350,L5644", "config": "[Kr].5s2", "shells": [ 2, 8, 18, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "✦", "kind": "Compounds", "use": "Strontium salts produce red colours in fireworks.", "why": "Atoms and ions can give recognisable colours when excited." }, { "number": 39, "symbol": "Y", "name": "Yttrium", "period": 5, "group": 3, "col": 3, "row": 5, "family": "Transition metal", "en": 1.22, "radius": 219.0, "ie": 6.21726, "ieStatus": "Measured / evaluated", "ieRaw": "6.21726", "ieUncertainty": "0.00010", "ieReference": "L8844,L2111,L9735", "config": "[Kr].4d.5s2", "shells": [ 2, 8, 18, 9, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "☷", "kind": "Compounds", "use": "Yttrium compounds are used in phosphors and laser crystals.", "why": "Rare-earth-related materials can convert energy into useful light." }, { "number": 40, "symbol": "Zr", "name": "Zirconium", "period": 5, "group": 4, "col": 4, "row": 5, "family": "Transition metal", "en": 1.33, "radius": 186.0, "ie": 6.634126, "ieStatus": "Measured / evaluated", "ieRaw": "6.634126", "ieUncertainty": "0.000005", "ieReference": "L21107", "config": "[Kr].4d2.5s2", "shells": [ 2, 8, 18, 10, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▰", "kind": "Alloys", "use": "Zirconium alloys are used for fuel cladding in many nuclear reactors.", "why": "Corrosion behaviour and interaction with neutrons both matter in this application." }, { "number": 41, "symbol": "Nb", "name": "Niobium", "period": 5, "group": 5, "col": 5, "row": 5, "family": "Transition metal", "en": 1.6, "radius": 207.0, "ie": 6.75885, "ieStatus": "Measured / evaluated", "ieRaw": "6.75885", "ieUncertainty": "0.00004", "ieReference": "L6829", "config": "[Kr].4d4.5s", "shells": [ 2, 8, 18, 12, 1 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⌁", "kind": "Alloys", "use": "Niobium-titanium alloys are used in superconducting magnets.", "why": "Some materials carry current without electrical resistance when cold enough." }, { "number": 42, "symbol": "Mo", "name": "Molybdenum", "period": 5, "group": 6, "col": 6, "row": 5, "family": "Transition metal", "en": 2.16, "radius": 209.0, "ie": 7.09243, "ieStatus": "Measured / evaluated", "ieRaw": "7.09243", "ieUncertainty": "0.00004", "ieReference": "L6829", "config": "[Kr].4d5.5s", "shells": [ 2, 8, 18, 13, 1 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▰", "kind": "Alloys", "use": "Molybdenum is added to steels used at high temperatures or in corrosive conditions.", "why": "Alloy chemistry can extend the useful life of equipment." }, { "number": 43, "symbol": "Tc", "name": "Technetium", "period": 5, "group": 7, "col": 7, "row": 5, "family": "Transition metal", "en": 1.9, "radius": 209.0, "ie": 7.11938, "ieStatus": "Measured / evaluated", "ieRaw": "7.11938", "ieUncertainty": "0.00003", "ieReference": "L15237", "config": "[Kr].4d5.5s2", "shells": [ 2, 8, 18, 13, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "＋", "kind": "Isotope / compound", "use": "Technetium-99m compounds are used as tracers in medical imaging.", "why": "A short-lived radioactive signal can reveal how organs are working." }, { "number": 44, "symbol": "Ru", "name": "Ruthenium", "period": 5, "group": 8, "col": 8, "row": 5, "family": "Transition metal", "en": 2.2, "radius": 207.0, "ie": 7.3605, "ieStatus": "Measured / evaluated", "ieRaw": "7.36050", "ieUncertainty": "0.00005", "ieReference": "L10032", "config": "[Kr].4d7.5s", "shells": [ 2, 8, 18, 15, 1 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⌁", "kind": "Element / compounds", "use": "Ruthenium is used in specialised electrical contacts and catalysts.", "why": "Small amounts can alter surface behaviour and chemical reaction rates." }, { "number": 45, "symbol": "Rh", "name": "Rhodium", "period": 5, "group": 9, "col": 9, "row": 5, "family": "Transition metal", "en": 2.28, "radius": 195.0, "ie": 7.4589, "ieStatus": "Measured / evaluated", "ieRaw": "7.45890", "ieUncertainty": "0.00005", "ieReference": "L10032", "config": "[Kr].4d8.5s", "shells": [ 2, 8, 18, 16, 1 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Element", "use": "Rhodium helps convert nitrogen oxides in vehicle catalytic converters.", "why": "Catalysts speed up reactions without being consumed overall." }, { "number": 46, "symbol": "Pd", "name": "Palladium", "period": 5, "group": 10, "col": 10, "row": 5, "family": "Transition metal", "en": 2.2, "radius": 202.0, "ie": 8.336839, "ieStatus": "Measured / evaluated", "ieRaw": "8.336839", "ieUncertainty": "0.000010", "ieReference": "L20363", "config": "[Kr].4d10", "shells": [ 2, 8, 18, 18 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Element", "use": "Palladium is used in catalytic converters and industrial catalysts.", "why": "Its surface helps reactant molecules change into other substances." }, { "number": 47, "symbol": "Ag", "name": "Silver", "period": 5, "group": 11, "col": 11, "row": 5, "family": "Transition metal", "en": 1.93, "radius": 172.0, "ie": 7.576234, "ieStatus": "Measured / evaluated", "ieRaw": "7.576234", "ieUncertainty": "0.000025", "ieReference": "L11835", "config": "[Kr].4d10.5s", "shells": [ 2, 8, 18, 18, 1 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⌁", "kind": "Element", "use": "Silver is used in electrical contacts, jewellery and reflective coatings.", "why": "High conductivity and reflectivity are useful material properties." }, { "number": 48, "symbol": "Cd", "name": "Cadmium", "period": 5, "group": 12, "col": 12, "row": 5, "family": "Transition metal", "en": 1.69, "radius": 158.0, "ie": 8.99382, "ieStatus": "Measured / evaluated", "ieRaw": "8.993820", "ieUncertainty": "0.000016", "ieReference": "L18843", "config": "[Kr].4d10.5s2", "shells": [ 2, 8, 18, 18, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▣", "kind": "Compounds", "use": "Cadmium compounds are used in some specialised batteries and solar cells.", "why": "Its useful electronic properties must be managed alongside serious toxicity." }, { "number": 49, "symbol": "In", "name": "Indium", "period": 5, "group": 13, "col": 13, "row": 5, "family": "Post-transition metal", "en": 1.78, "radius": 193.0, "ie": 5.7863558, "ieStatus": "Measured / evaluated", "ieRaw": "5.7863558", "ieUncertainty": "0.0000005", "ieReference": "L21649", "config": "[Cd].5p", "shells": [ 2, 8, 18, 18, 3 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▱", "kind": "Compounds", "use": "Indium tin oxide makes transparent conducting coatings in many screens.", "why": "A material can let light through and still conduct electricity." }, { "number": 50, "symbol": "Sn", "name": "Tin", "period": 5, "group": 14, "col": 14, "row": 5, "family": "Post-transition metal", "en": 1.96, "radius": 217.0, "ie": 7.343918, "ieStatus": "Measured / evaluated", "ieRaw": "7.343918", "ieUncertainty": "0.000012", "ieReference": "L3936", "config": "[Cd].5p2", "shells": [ 2, 8, 18, 18, 4 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⌁", "kind": "Element / alloys", "use": "Tin is used in solders and protective coatings.", "why": "A low-melting alloy can join electronic components." }, { "number": 51, "symbol": "Sb", "name": "Antimony", "period": 5, "group": 15, "col": 15, "row": 5, "family": "Metalloid", "en": 2.05, "radius": 206.0, "ie": 8.608389, "ieStatus": "Measured / evaluated", "ieRaw": "8.608389", "ieUncertainty": "0.000012", "ieReference": "L8844,L6684", "config": "[Cd].5p3", "shells": [ 2, 8, 18, 18, 5 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▱", "kind": "Compounds / alloys", "use": "Antimony compounds are used in some flame-retardant systems.", "why": "It shows how small ingredients can change a material's behaviour." }, { "number": 52, "symbol": "Te", "name": "Tellurium", "period": 5, "group": 16, "col": 16, "row": 5, "family": "Metalloid", "en": 2.1, "radius": 206.0, "ie": 9.009808, "ieStatus": "Measured / evaluated", "ieRaw": "9.009808", "ieUncertainty": "0.000006", "ieReference": "L21109", "config": "[Cd].5p4", "shells": [ 2, 8, 18, 18, 6 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▦", "kind": "Compounds", "use": "Cadmium telluride is used in thin-film solar cells.", "why": "Compound semiconductors can turn light into electrical energy." }, { "number": 53, "symbol": "I", "name": "Iodine", "period": 5, "group": 17, "col": 17, "row": 5, "family": "Halogen", "en": 2.66, "radius": 198.0, "ie": 10.451236, "ieStatus": "Measured / evaluated", "ieRaw": "10.451236", "ieUncertainty": "0.000025", "ieReference": "L13998,L22518", "config": "[Cd].5p5", "shells": [ 2, 8, 18, 18, 7 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "＋", "kind": "Compounds", "use": "Iodine compounds are used in antiseptics and iodised salt.", "why": "The body needs a small amount of iodine for thyroid hormones." }, { "number": 54, "symbol": "Xe", "name": "Xenon", "period": 5, "group": 18, "col": 18, "row": 5, "family": "Noble gas", "en": 2.6, "radius": 216.0, "ie": 12.1298437, "ieStatus": "Measured / evaluated", "ieRaw": "12.1298437", "ieUncertainty": "0.0000015", "ieReference": "L12013,L9794,L6426", "config": "[Cd].5p6", "shells": [ 2, 8, 18, 18, 8 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Gas", "icon": "☷", "kind": "Element", "use": "Xenon is used in flash lamps and some spacecraft ion thrusters.", "why": "The same gas can support light generation and electric propulsion." }, { "number": 55, "symbol": "Cs", "name": "Caesium", "period": 6, "group": 1, "col": 1, "row": 6, "family": "Alkali metal", "en": 0.79, "radius": 343.0, "ie": 3.89390572743, "ieStatus": "Measured / evaluated", "ieRaw": "3.89390572743", "ieUncertainty": "0.00000000017", "ieReference": "L19479", "config": "[Xe].6s", "shells": [ 2, 8, 18, 18, 8, 1 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "◷", "kind": "Isotope / element", "use": "The transition in caesium-133 atoms defines the SI second.", "why": "An atomic property provides a shared reference for time." }, { "number": 56, "symbol": "Ba", "name": "Barium", "period": 6, "group": 2, "col": 2, "row": 6, "family": "Alkaline earth metal", "en": 0.89, "radius": 268.0, "ie": 5.2116646, "ieStatus": "Measured / evaluated", "ieRaw": "5.2116646", "ieUncertainty": "0.0000012", "ieReference": "L6347,L9224", "config": "[Xe].6s2", "shells": [ 2, 8, 18, 18, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "＋", "kind": "Compound", "use": "Barium sulfate is used as a contrast material in some X-ray examinations.", "why": "This very insoluble compound behaves differently from soluble, toxic barium salts." }, { "number": 57, "symbol": "La", "name": "Lanthanum", "period": 6, "group": null, "col": 3, "row": 9, "family": "Lanthanide", "en": 1.1, "radius": 240.0, "ie": 5.5769, "ieStatus": "Measured / evaluated", "ieRaw": "5.5769", "ieUncertainty": "0.0006", "ieReference": "L3974,L16228", "config": "[Xe].5d.6s2", "shells": [ 2, 8, 18, 18, 9, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▱", "kind": "Compounds", "use": "Lanthanum compounds are used in some optical glasses and catalysts.", "why": "The lanthanide series supports many specialised material technologies." }, { "number": 58, "symbol": "Ce", "name": "Cerium", "period": 6, "group": null, "col": 4, "row": 9, "family": "Lanthanide", "en": 1.12, "radius": 235.0, "ie": 5.5386, "ieStatus": "Measured / evaluated", "ieRaw": "5.5386", "ieUncertainty": "0.0004", "ieReference": "L4277", "config": "[Xe].4f.5d.6s2", "shells": [ 2, 8, 18, 19, 9, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▱", "kind": "Compound", "use": "Cerium oxide is used for polishing glass.", "why": "Surface chemistry can make a powder useful for precision finishing." }, { "number": 59, "symbol": "Pr", "name": "Praseodymium", "period": 6, "group": null, "col": 5, "row": 9, "family": "Lanthanide", "en": 1.13, "radius": 239.0, "ie": 5.4702, "ieStatus": "Estimated (semi-empirical)", "ieRaw": "5.4702", "ieUncertainty": "0.0004", "ieReference": "L19006", "config": "[Xe].4f3.6s2", "shells": [ 2, 8, 18, 21, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "◎", "kind": "Alloys", "use": "Praseodymium is used in some strong permanent magnets.", "why": "Rare-earth electronic structures support useful magnetic materials." }, { "number": 60, "symbol": "Nd", "name": "Neodymium", "period": 6, "group": null, "col": 6, "row": 9, "family": "Lanthanide", "en": 1.14, "radius": 229.0, "ie": 5.52475, "ieStatus": "Measured / evaluated", "ieRaw": "5.52475", "ieUncertainty": "0.00005", "ieReference": "L23155", "config": "[Xe].4f4.6s2", "shells": [ 2, 8, 18, 22, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "◎", "kind": "Alloys", "use": "Neodymium-iron-boron magnets are used in motors, headphones and wind turbines.", "why": "Strong magnets can help make compact electromechanical devices." }, { "number": 61, "symbol": "Pm", "name": "Promethium", "period": 6, "group": null, "col": 7, "row": 9, "family": "Lanthanide", "en": null, "radius": 236.0, "ie": 5.58187, "ieStatus": "Measured / evaluated", "ieRaw": "5.58187", "ieUncertainty": "0.00004", "ieReference": "L20992", "config": "[Xe].4f5.6s2", "shells": [ 2, 8, 18, 23, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Isotope / research", "use": "Promethium-147 has been used in specialised nuclear batteries and research.", "why": "All promethium isotopes are radioactive, limiting everyday uses." }, { "number": 62, "symbol": "Sm", "name": "Samarium", "period": 6, "group": null, "col": 8, "row": 9, "family": "Lanthanide", "en": 1.17, "radius": 229.0, "ie": 5.643722, "ieStatus": "Measured / evaluated", "ieRaw": "5.643722", "ieUncertainty": "0.000021", "ieReference": "L21624", "config": "[Xe].4f6.6s2", "shells": [ 2, 8, 18, 24, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "◎", "kind": "Alloys", "use": "Samarium-cobalt magnets are used where heat resistance matters.", "why": "Different magnet alloys suit different operating conditions." }, { "number": 63, "symbol": "Eu", "name": "Europium", "period": 6, "group": null, "col": 9, "row": 9, "family": "Lanthanide", "en": null, "radius": 233.0, "ie": 5.670385, "ieStatus": "Measured / evaluated", "ieRaw": "5.670385", "ieUncertainty": "0.000005", "ieReference": "L13382", "config": "[Xe].4f7.6s2", "shells": [ 2, 8, 18, 25, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "☷", "kind": "Compounds", "use": "Europium compounds make red light in some display and lighting phosphors.", "why": "Electron energy changes can produce specific colours." }, { "number": 64, "symbol": "Gd", "name": "Gadolinium", "period": 6, "group": null, "col": 10, "row": 9, "family": "Lanthanide", "en": 1.2, "radius": 237.0, "ie": 6.1498, "ieStatus": "Measured / evaluated", "ieRaw": "6.14980", "ieUncertainty": "0.00004", "ieReference": "L11798", "config": "[Xe].4f7.5d.6s2", "shells": [ 2, 8, 18, 25, 9, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "＋", "kind": "Compounds", "use": "Gadolinium-containing chelates are used in some MRI contrast agents.", "why": "Carefully designed compounds can make magnetic properties useful in imaging." }, { "number": 65, "symbol": "Tb", "name": "Terbium", "period": 6, "group": null, "col": 11, "row": 9, "family": "Lanthanide", "en": null, "radius": 221.0, "ie": 5.8638, "ieStatus": "Measured / evaluated", "ieRaw": "5.8638", "ieUncertainty": "0.0006", "ieReference": "L4277", "config": "[Xe].4f9.6s2", "shells": [ 2, 8, 18, 27, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "☷", "kind": "Compounds", "use": "Terbium compounds produce green light in some phosphors.", "why": "Rare-earth ions help control the colour of emitted light." }, { "number": 66, "symbol": "Dy", "name": "Dysprosium", "period": 6, "group": null, "col": 12, "row": 9, "family": "Lanthanide", "en": 1.22, "radius": 229.0, "ie": 5.939061, "ieStatus": "Measured / evaluated", "ieRaw": "5.939061", "ieUncertainty": "0.000006", "ieReference": "L22122", "config": "[Xe].4f10.6s2", "shells": [ 2, 8, 18, 28, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "◎", "kind": "Alloys", "use": "Dysprosium is added to some permanent magnets to improve performance when hot.", "why": "Temperature behaviour matters as much as room-temperature strength." }, { "number": 67, "symbol": "Ho", "name": "Holmium", "period": 6, "group": null, "col": 13, "row": 9, "family": "Lanthanide", "en": 1.23, "radius": 216.0, "ie": 6.0215, "ieStatus": "Measured / evaluated", "ieRaw": "6.0215", "ieUncertainty": "0.0006", "ieReference": "L4277", "config": "[Xe].4f11.6s2", "shells": [ 2, 8, 18, 29, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⌁", "kind": "Compounds", "use": "Holmium-doped laser crystals are used in some medical lasers.", "why": "Adding selected ions can tune the light a laser produces." }, { "number": 68, "symbol": "Er", "name": "Erbium", "period": 6, "group": null, "col": 14, "row": 9, "family": "Lanthanide", "en": 1.24, "radius": 235.0, "ie": 6.1077, "ieStatus": "Measured / evaluated", "ieRaw": "6.1077", "ieUncertainty": "0.0010", "ieReference": "L4277", "config": "[Xe].4f12.6s2", "shells": [ 2, 8, 18, 30, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⌁", "kind": "Compounds", "use": "Erbium-doped fibre amplifiers strengthen optical communication signals.", "why": "Its optical transitions help light carry information over long distances." }, { "number": 69, "symbol": "Tm", "name": "Thulium", "period": 6, "group": null, "col": 15, "row": 9, "family": "Lanthanide", "en": 1.25, "radius": 227.0, "ie": 6.184402, "ieStatus": "Measured / evaluated", "ieRaw": "6.184402", "ieUncertainty": "0.000009", "ieReference": "L22274", "config": "[Xe].4f13.6s2", "shells": [ 2, 8, 18, 31, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⌁", "kind": "Compounds", "use": "Thulium-doped materials are used in specialised lasers.", "why": "Less common elements can provide specific useful wavelengths." }, { "number": 70, "symbol": "Yb", "name": "Ytterbium", "period": 6, "group": null, "col": 16, "row": 9, "family": "Lanthanide", "en": null, "radius": 242.0, "ie": 6.25416, "ieStatus": "Measured / evaluated", "ieRaw": "6.254160", "ieUncertainty": "0.000012", "ieReference": "L4980", "config": "[Xe].4f14.6s2", "shells": [ 2, 8, 18, 32, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⌁", "kind": "Compounds", "use": "Ytterbium-doped fibre lasers are used in industrial processing.", "why": "Its electronic structure makes efficient laser materials possible." }, { "number": 71, "symbol": "Lu", "name": "Lutetium", "period": 6, "group": null, "col": 17, "row": 9, "family": "Lanthanide", "en": 1.27, "radius": 221.0, "ie": 5.425871, "ieStatus": "Measured / evaluated", "ieRaw": "5.425871", "ieUncertainty": "0.000012", "ieReference": "L10494,L1638", "config": "[Xe].4f14.5d.6s2", "shells": [ 2, 8, 18, 32, 9, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "＋", "kind": "Isotope / compounds", "use": "Lutetium-177 compounds are used in some targeted cancer treatments.", "why": "A radioactive isotope can deliver radiation to selected tissues." }, { "number": 72, "symbol": "Hf", "name": "Hafnium", "period": 6, "group": 4, "col": 4, "row": 6, "family": "Transition metal", "en": 1.3, "radius": 212.0, "ie": 6.82507, "ieStatus": "Measured / evaluated", "ieRaw": "6.825070", "ieUncertainty": "0.000012", "ieReference": "L14027,L10033", "config": "[Xe].4f14.5d2.6s2", "shells": [ 2, 8, 18, 32, 10, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▰", "kind": "Element", "use": "Hafnium is used in some nuclear-reactor control rods.", "why": "It absorbs neutrons effectively, unlike the chemically similar zirconium." }, { "number": 73, "symbol": "Ta", "name": "Tantalum", "period": 6, "group": 5, "col": 5, "row": 6, "family": "Transition metal", "en": 1.5, "radius": 217.0, "ie": 7.549571, "ieStatus": "Measured / evaluated", "ieRaw": "7.549571", "ieUncertainty": "0.000025", "ieReference": "L13153", "config": "[Xe].4f14.5d3.6s2", "shells": [ 2, 8, 18, 32, 11, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▣", "kind": "Element / oxide", "use": "Tantalum and its oxide are used in compact electronic capacitors.", "why": "A stable insulating oxide can help store electrical charge." }, { "number": 74, "symbol": "W", "name": "Tungsten", "period": 6, "group": 6, "col": 6, "row": 6, "family": "Transition metal", "en": 2.36, "radius": 210.0, "ie": 7.86403, "ieStatus": "Measured / evaluated", "ieRaw": "7.86403", "ieUncertainty": "0.00010", "ieReference": "L11604", "config": "[Xe].4f14.5d4.6s2", "shells": [ 2, 8, 18, 32, 12, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "✦", "kind": "Element", "use": "Tungsten is used in high-temperature parts and some lamp filaments.", "why": "Its very high melting point makes it useful in extreme heat." }, { "number": 75, "symbol": "Re", "name": "Rhenium", "period": 6, "group": 7, "col": 7, "row": 6, "family": "Transition metal", "en": 1.9, "radius": 217.0, "ie": 7.83352, "ieStatus": "Measured / evaluated", "ieRaw": "7.83352", "ieUncertainty": "0.00011", "ieReference": "L11604", "config": "[Xe].4f14.5d5.6s2", "shells": [ 2, 8, 18, 32, 13, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "✈", "kind": "Alloys", "use": "Rhenium is used in some high-temperature turbine superalloys.", "why": "Very small alloying additions can improve performance in hot engines." }, { "number": 76, "symbol": "Os", "name": "Osmium", "period": 6, "group": 8, "col": 8, "row": 6, "family": "Transition metal", "en": 2.2, "radius": 216.0, "ie": 8.43823, "ieStatus": "Measured / evaluated", "ieRaw": "8.43823", "ieUncertainty": "0.00020", "ieReference": "L8105", "config": "[Xe].4f14.5d6.6s2", "shells": [ 2, 8, 18, 32, 14, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▰", "kind": "Alloys", "use": "Osmium has been used in specialised hard, wear-resistant alloys.", "why": "Dense metals can have useful niche roles; some osmium compounds are highly hazardous." }, { "number": 77, "symbol": "Ir", "name": "Iridium", "period": 6, "group": 9, "col": 9, "row": 6, "family": "Transition metal", "en": 2.2, "radius": 202.0, "ie": 8.96702, "ieStatus": "Measured / evaluated", "ieRaw": "8.96702", "ieUncertainty": "0.00022", "ieReference": "L8105", "config": "[Xe].4f14.5d7.6s2", "shells": [ 2, 8, 18, 32, 15, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "✦", "kind": "Element / alloys", "use": "Iridium is used in durable spark-plug tips and specialised crucibles.", "why": "Resistance to heat and corrosion supports demanding applications." }, { "number": 78, "symbol": "Pt", "name": "Platinum", "period": 6, "group": 10, "col": 10, "row": 6, "family": "Transition metal", "en": 2.28, "radius": 209.0, "ie": 8.95883, "ieStatus": "Measured / evaluated", "ieRaw": "8.95883", "ieUncertainty": "0.00010", "ieReference": "L9735,L11689", "config": "[Xe].4f14.5d9.6s", "shells": [ 2, 8, 18, 32, 17, 1 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Element", "use": "Platinum is used in catalysts, including some fuel cells.", "why": "Its surface can help chemical reactions transfer energy efficiently." }, { "number": 79, "symbol": "Au", "name": "Gold", "period": 6, "group": 11, "col": 11, "row": 6, "family": "Transition metal", "en": 2.54, "radius": 166.0, "ie": 9.225554, "ieStatus": "Measured / evaluated", "ieRaw": "9.225554", "ieUncertainty": "0.000004", "ieReference": "L12088", "config": "[Xe].4f14.5d10.6s", "shells": [ 2, 8, 18, 32, 18, 1 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⌁", "kind": "Element", "use": "Gold is used on some electronic connectors and in jewellery.", "why": "It resists corrosion and makes reliable contact surfaces." }, { "number": 80, "symbol": "Hg", "name": "Mercury", "period": 6, "group": 12, "col": 12, "row": 6, "family": "Transition metal", "en": 2.0, "radius": 209.0, "ie": 10.437504, "ieStatus": "Measured / evaluated", "ieRaw": "10.437504", "ieUncertainty": "0.000006", "ieReference": "L11931,L11984", "config": "[Xe].4f14.5d10.6s2", "shells": [ 2, 8, 18, 32, 18, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Liquid", "icon": "☷", "kind": "Element", "use": "Mercury has been used in fluorescent lamps and measuring instruments.", "why": "Its unusual liquid state is useful, but toxicity has driven replacement in many products." }, { "number": 81, "symbol": "Tl", "name": "Thallium", "period": 6, "group": 13, "col": 13, "row": 6, "family": "Post-transition metal", "en": 1.62, "radius": 196.0, "ie": 6.1082873, "ieStatus": "Measured / evaluated", "ieRaw": "6.1082873", "ieUncertainty": "0.0000012", "ieReference": "L16353", "config": "[Hg].6p", "shells": [ 2, 8, 18, 32, 18, 3 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▦", "kind": "Compounds", "use": "Thallium compounds are used in some specialised detectors and optical materials.", "why": "Niche electronic properties do not remove the need to manage severe toxicity." }, { "number": 82, "symbol": "Pb", "name": "Lead", "period": 6, "group": 14, "col": 14, "row": 6, "family": "Post-transition metal", "en": 2.33, "radius": 202.0, "ie": 7.4166799, "ieStatus": "Measured / evaluated", "ieRaw": "7.4166799", "ieUncertainty": "0.0000006", "ieReference": "L11569", "config": "[Hg].6p2", "shells": [ 2, 8, 18, 32, 18, 4 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "▣", "kind": "Element / compounds", "use": "Lead and lead compounds are used in lead-acid batteries.", "why": "A familiar battery chemistry relies on reactions between different lead materials." }, { "number": 83, "symbol": "Bi", "name": "Bismuth", "period": 6, "group": 15, "col": 15, "row": 6, "family": "Post-transition metal", "en": 2.02, "radius": 207.0, "ie": 7.285516, "ieStatus": "Measured / evaluated", "ieRaw": "7.285516", "ieUncertainty": "0.000006", "ieReference": "L10664,L6247", "config": "[Hg].6p3", "shells": [ 2, 8, 18, 32, 18, 5 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "＋", "kind": "Compounds", "use": "Some bismuth compounds are used in medicines for stomach problems.", "why": "The properties of a compound depend on its full chemical structure." }, { "number": 84, "symbol": "Po", "name": "Polonium", "period": 6, "group": 16, "col": 16, "row": 6, "family": "Metalloid", "en": 2.0, "radius": 197.0, "ie": 8.41807, "ieStatus": "Measured / evaluated", "ieRaw": "8.418070", "ieUncertainty": "0.000004", "ieReference": "L20887,L20886", "config": "[Hg].6p4", "shells": [ 2, 8, 18, 32, 18, 6 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Isotope / specialist", "use": "Polonium-210 has been used in specialised static-elimination devices.", "why": "Intense radioactivity restricts its use to tightly controlled settings." }, { "number": 85, "symbol": "At", "name": "Astatine", "period": 6, "group": 17, "col": 17, "row": 6, "family": "Halogen", "en": 2.2, "radius": 202.0, "ie": 9.31751, "ieStatus": "Measured / evaluated", "ieRaw": "9.31751", "ieUncertainty": "0.00008", "ieReference": "L18394", "config": "[Hg].6p5", "shells": [ 2, 8, 18, 32, 18, 7 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "＋", "kind": "Isotope / research", "use": "Astatine-211 is being studied for targeted cancer therapy.", "why": "Very short-lived atoms can still have valuable research roles." }, { "number": 86, "symbol": "Rn", "name": "Radon", "period": 6, "group": 18, "col": 18, "row": 6, "family": "Noble gas", "en": null, "radius": 220.0, "ie": 10.7485, "ieStatus": "Measured / evaluated", "ieRaw": "10.74850", "ieUncertainty": null, "ieReference": "L272,L7432", "config": "[Hg].6p6", "shells": [ 2, 8, 18, 32, 18, 8 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Gas", "icon": "⚗", "kind": "Research", "use": "Radon is studied in radiation science and environmental monitoring.", "why": "It is a naturally occurring radioactive gas and an important indoor health hazard." }, { "number": 87, "symbol": "Fr", "name": "Francium", "period": 7, "group": 1, "col": 1, "row": 7, "family": "Alkali metal", "en": 0.7, "radius": 348.0, "ie": 4.0727411, "ieStatus": "Measured / evaluated", "ieRaw": "4.0727411", "ieUncertainty": "0.0000011", "ieReference": "L10714", "config": "[Rn].7s", "shells": [ 2, 8, 18, 32, 18, 8, 1 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Research", "use": "Francium atoms are studied in atomic-physics experiments.", "why": "Its rarity and short half-lives make everyday applications impractical." }, { "number": 88, "symbol": "Ra", "name": "Radium", "period": 7, "group": 2, "col": 2, "row": 7, "family": "Alkaline earth metal", "en": 0.9, "radius": 283.0, "ie": 5.2784239, "ieStatus": "Measured / evaluated", "ieRaw": "5.2784239", "ieUncertainty": "0.0000025", "ieReference": "L4979", "config": "[Rn].7s2", "shells": [ 2, 8, 18, 32, 18, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "＋", "kind": "Isotope / medicine", "use": "Radium-223 is used in certain cancer treatments.", "why": "The isotope, its radiation and its chemical behaviour determine its medical role." }, { "number": 89, "symbol": "Ac", "name": "Actinium", "period": 7, "group": null, "col": 3, "row": 10, "family": "Actinide", "en": 1.1, "radius": 260.0, "ie": 5.380235, "ieStatus": "Measured / evaluated", "ieRaw": "5.380235", "ieUncertainty": "0.000012", "ieReference": "L22136,L17893", "config": "[Rn].6d.7s2", "shells": [ 2, 8, 18, 32, 18, 9, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "＋", "kind": "Isotope / research", "use": "Actinium-225 is being investigated and used in targeted alpha-therapy programmes.", "why": "Radioactive isotopes can link nuclear physics to medical research." }, { "number": 90, "symbol": "Th", "name": "Thorium", "period": 7, "group": null, "col": 4, "row": 10, "family": "Actinide", "en": 1.3, "radius": 237.0, "ie": 6.3067, "ieStatus": "Measured / evaluated", "ieRaw": "6.30670", "ieUncertainty": "0.00025", "ieReference": "L15992", "config": "[Rn].6d2.7s2", "shells": [ 2, 8, 18, 32, 18, 10, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚡", "kind": "Element / research", "use": "Thorium is studied as a potential nuclear-fuel resource.", "why": "Using it as fuel requires a suitable reactor and fuel cycle." }, { "number": 91, "symbol": "Pa", "name": "Protactinium", "period": 7, "group": null, "col": 5, "row": 10, "family": "Actinide", "en": 1.5, "radius": 243.0, "ie": 5.89, "ieStatus": "Estimated (semi-empirical)", "ieRaw": "5.89", "ieUncertainty": "0.12", "ieReference": "L16359", "config": "[Rn].5f2.6d.7s2", "shells": [ 2, 8, 18, 32, 20, 9, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Research", "use": "Protactinium is used mainly in scientific research, including isotope studies.", "why": "Rare radioactive elements help scientists understand nuclear processes." }, { "number": 92, "symbol": "U", "name": "Uranium", "period": 7, "group": null, "col": 6, "row": 10, "family": "Actinide", "en": 1.38, "radius": 240.0, "ie": 6.19405, "ieStatus": "Measured / evaluated", "ieRaw": "6.19405", "ieUncertainty": "0.00006", "ieReference": "L5494,L7765", "config": "[Rn].5f3.6d.7s2", "shells": [ 2, 8, 18, 32, 21, 9, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚡", "kind": "Isotopes / compounds", "use": "Uranium dioxide containing suitable uranium isotopes is fuel in many nuclear reactors.", "why": "Isotope composition matters as well as the element's identity." }, { "number": 93, "symbol": "Np", "name": "Neptunium", "period": 7, "group": null, "col": 7, "row": 10, "family": "Actinide", "en": 1.36, "radius": 221.0, "ie": 6.265608, "ieStatus": "Measured / evaluated", "ieRaw": "6.265608", "ieUncertainty": "0.000019", "ieReference": "L23048", "config": "[Rn].5f4.6d.7s2", "shells": [ 2, 8, 18, 32, 22, 9, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Isotope / specialist", "use": "Neptunium-237 can be used as a starting material to make plutonium-238.", "why": "Nuclear reactions can turn one element into another." }, { "number": 94, "symbol": "Pu", "name": "Plutonium", "period": 7, "group": null, "col": 8, "row": 10, "family": "Actinide", "en": 1.28, "radius": 243.0, "ie": 6.02576, "ieStatus": "Measured / evaluated", "ieRaw": "6.02576", "ieUncertainty": "0.00025", "ieReference": "L15992,L11260", "config": "[Rn].5f6.7s2", "shells": [ 2, 8, 18, 32, 24, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚡", "kind": "Isotope / compound", "use": "Plutonium-238 dioxide supplies heat in some spacecraft power systems.", "why": "Radioactive decay can provide long-lasting heat far from the Sun." }, { "number": 95, "symbol": "Am", "name": "Americium", "period": 7, "group": null, "col": 9, "row": 10, "family": "Actinide", "en": 1.3, "radius": 244.0, "ie": 5.97381, "ieStatus": "Measured / evaluated", "ieRaw": "5.97381", "ieUncertainty": "0.00025", "ieReference": "L15992", "config": "[Rn].5f7.7s2", "shells": [ 2, 8, 18, 32, 25, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⌂", "kind": "Isotope / compound", "use": "Americium-241 oxide is used in some ionisation smoke detectors.", "why": "A small radioactive source can help a detector sense smoke." }, { "number": 96, "symbol": "Cm", "name": "Curium", "period": 7, "group": null, "col": 10, "row": 10, "family": "Actinide", "en": 1.3, "radius": 245.0, "ie": 5.992241, "ieStatus": "Measured / evaluated", "ieRaw": "5.992241", "ieUncertainty": "0.000020", "ieReference": "L22423", "config": "[Rn].5f7.6d.7s2", "shells": [ 2, 8, 18, 32, 25, 9, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Isotope / research", "use": "Curium isotopes are used in research and some alpha-particle instruments.", "why": "Radioactive emissions can probe materials and nuclear structure." }, { "number": 97, "symbol": "Bk", "name": "Berkelium", "period": 7, "group": null, "col": 11, "row": 10, "family": "Actinide", "en": 1.3, "radius": 244.0, "ie": 6.19785, "ieStatus": "Measured / evaluated", "ieRaw": "6.19785", "ieUncertainty": "0.00025", "ieReference": "L15992", "config": "[Rn].5f9.7s2", "shells": [ 2, 8, 18, 32, 27, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Isotope / research", "use": "Berkelium-249 has been used as a target to create heavier elements.", "why": "Making new elements requires carefully chosen target nuclei." }, { "number": 98, "symbol": "Cf", "name": "Californium", "period": 7, "group": null, "col": 12, "row": 10, "family": "Actinide", "en": 1.3, "radius": 245.0, "ie": 6.281878, "ieStatus": "Measured / evaluated", "ieRaw": "6.281878", "ieUncertainty": "0.000006", "ieReference": "L22260", "config": "[Rn].5f10.7s2", "shells": [ 2, 8, 18, 32, 28, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Isotope / specialist", "use": "Californium-252 is used as a neutron source in specialised instruments.", "why": "Some radioactive nuclei release neutrons as they split." }, { "number": 99, "symbol": "Es", "name": "Einsteinium", "period": 7, "group": null, "col": 13, "row": 10, "family": "Actinide", "en": 1.3, "radius": 245.0, "ie": 6.3684, "ieStatus": "Measured / evaluated", "ieRaw": "6.36840", "ieUncertainty": "0.00006", "ieReference": "L22449", "config": "[Rn].5f11.7s2", "shells": [ 2, 8, 18, 32, 29, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Research", "use": "Einsteinium is made in tiny quantities for studies of heavy-element chemistry.", "why": "It tests how familiar chemical patterns hold up in very heavy atoms." }, { "number": 100, "symbol": "Fm", "name": "Fermium", "period": 7, "group": null, "col": 14, "row": 10, "family": "Actinide", "en": 1.3, "radius": null, "ie": 6.5, "ieStatus": "Estimated (semi-empirical)", "ieRaw": "6.50", "ieUncertainty": "0.07", "ieReference": "L16359", "config": "[Rn].5f12.7s2", "shells": [ 2, 8, 18, 32, 30, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Research", "use": "Fermium has no everyday commercial use; its isotopes are studied in laboratories.", "why": "Its short-lived nuclei help test ideas about nuclear stability." }, { "number": 101, "symbol": "Md", "name": "Mendelevium", "period": 7, "group": null, "col": 15, "row": 10, "family": "Actinide", "en": 1.3, "radius": null, "ie": 6.58, "ieStatus": "Estimated (semi-empirical)", "ieRaw": "6.58", "ieUncertainty": "0.07", "ieReference": "L16359", "config": "[Rn].5f13.7s2", "shells": [ 2, 8, 18, 32, 31, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Research", "use": "Mendelevium is studied a few atoms at a time in heavy-element experiments.", "why": "Chemistry can be investigated even with extremely small samples." }, { "number": 102, "symbol": "No", "name": "Nobelium", "period": 7, "group": null, "col": 16, "row": 10, "family": "Actinide", "en": 1.3, "radius": null, "ie": 6.62621, "ieStatus": "Measured / evaluated", "ieRaw": "6.62621", "ieUncertainty": "0.00005", "ieReference": "L20870", "config": "[Rn].5f14.7s2", "shells": [ 2, 8, 18, 32, 32, 8, 2 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Research", "use": "Nobelium is used in research on heavy atoms and nuclei.", "why": "Its measured ionisation energy helps test atomic calculations." }, { "number": 103, "symbol": "Lr", "name": "Lawrencium", "period": 7, "group": null, "col": 17, "row": 10, "family": "Actinide", "en": 1.3, "radius": null, "ie": 4.96, "ieStatus": "Measured / evaluated", "ieRaw": "4.96", "ieUncertainty": "0.05", "ieReference": "L21372", "config": "[Rn].5f14.7s2.7p", "shells": [ 2, 8, 18, 32, 32, 8, 3 ], "shellStatus": "Tabulated ground-state configuration", "configSource": "NIST ASD", "state": "Solid", "icon": "⚗", "kind": "Research", "use": "Lawrencium is studied in experiments on the end of the actinide series.", "why": "Its electron configuration shows why simple filling rules have exceptions." }, { "number": 104, "symbol": "Rf", "name": "Rutherfordium", "period": 7, "group": 4, "col": 4, "row": 7, "family": "Transition metal", "en": null, "radius": null, "ie": 6.02, "ieStatus": "Predicted (theory)", "ieRaw": "6.02", "ieUncertainty": "0.04", "ieReference": "L19691", "config": "[Rn].5f14.6d2.7s2", "shells": [ 2, 8, 18, 32, 32, 10, 2 ], "shellStatus": "Predicted configuration", "configSource": "NIST ASD", "state": "Bulk state unmeasured", "icon": "⚗", "kind": "Research", "use": "Rutherfordium is used only in research, including comparisons with zirconium and hafnium.", "why": "Experiments test whether family relationships persist in superheavy elements.", "pubchemState": "Solid" }, { "number": 105, "symbol": "Db", "name": "Dubnium", "period": 7, "group": 5, "col": 5, "row": 7, "family": "Transition metal", "en": null, "radius": null, "ie": 6.8, "ieStatus": "Predicted (theory)", "ieRaw": "6.8", "ieUncertainty": "0.5", "ieReference": "L12825", "config": "[Rn].5f14.6d3.7s2", "shells": [ 2, 8, 18, 32, 32, 11, 2 ], "shellStatus": "Predicted configuration", "configSource": "NIST ASD", "state": "Bulk state unmeasured", "icon": "⚗", "kind": "Research", "use": "Dubnium is used in laboratory studies of superheavy-element chemistry.", "why": "Tiny samples can still reveal chemical similarities and differences.", "pubchemState": "Solid" }, { "number": 106, "symbol": "Sg", "name": "Seaborgium", "period": 7, "group": 6, "col": 6, "row": 7, "family": "Transition metal", "en": null, "radius": null, "ie": 7.8, "ieStatus": "Estimated (semi-empirical)", "ieRaw": "7.8", "ieUncertainty": "0.5", "ieReference": "L7830", "config": "[Rn].5f14.6d4.7s2", "shells": [ 2, 8, 18, 32, 32, 12, 2 ], "shellStatus": "Predicted configuration", "configSource": "NIST ASD", "state": "Bulk state unmeasured", "icon": "⚗", "kind": "Research", "use": "Seaborgium is used in experiments comparing very heavy atoms with lighter group-6 elements.", "why": "Relativistic effects become increasingly important for heavy atoms.", "pubchemState": "Solid" }, { "number": 107, "symbol": "Bh", "name": "Bohrium", "period": 7, "group": 7, "col": 7, "row": 7, "family": "Transition metal", "en": null, "radius": null, "ie": 7.7, "ieStatus": "Estimated (semi-empirical)", "ieRaw": "7.7", "ieUncertainty": "0.5", "ieReference": "L13544", "config": "[Rn].5f14.6d5.7s2", "shells": [ 2, 8, 18, 32, 32, 13, 2 ], "shellStatus": "Predicted configuration", "configSource": "NIST ASD", "state": "Bulk state unmeasured", "icon": "⚗", "kind": "Research", "use": "Bohrium is made for studies of nuclear decay and superheavy chemistry.", "why": "Its position suggests relationships that experiments must test.", "pubchemState": "Solid" }, { "number": 108, "symbol": "Hs", "name": "Hassium", "period": 7, "group": 8, "col": 8, "row": 7, "family": "Transition metal", "en": null, "radius": null, "ie": 7.6, "ieStatus": "Estimated (semi-empirical)", "ieRaw": "7.6", "ieUncertainty": "0.5", "ieReference": "L13544", "config": "[Rn].5f14.6d6.7s2", "shells": [ 2, 8, 18, 32, 32, 14, 2 ], "shellStatus": "Predicted configuration", "configSource": "NIST ASD", "state": "Bulk state unmeasured", "icon": "⚗", "kind": "Research", "use": "Hassium is used in experiments on very heavy nuclei and chemical behaviour.", "why": "The table guides questions even when only a few atoms exist.", "pubchemState": "Solid" }, { "number": 109, "symbol": "Mt", "name": "Meitnerium", "period": 7, "group": 9, "col": 9, "row": 7, "family": "Transition metal", "en": null, "radius": null, "ie": null, "ieStatus": "Data unavailable", "ieRaw": null, "ieUncertainty": null, "ieReference": null, "config": "[Rn]7s2 5f14 6d7 (calculated)", "shells": [ 2, 8, 18, 32, 32, 15, 2 ], "shellStatus": "Predicted configuration", "configSource": "PubChem", "state": "Bulk state unmeasured", "icon": "⚗", "kind": "Research", "use": "Meitnerium is made only for nuclear research; no everyday use is known.", "why": "Its identity is established even though many properties remain unknown.", "pubchemState": "Solid" }, { "number": 110, "symbol": "Ds", "name": "Darmstadtium", "period": 7, "group": 10, "col": 10, "row": 7, "family": "Transition metal", "en": null, "radius": null, "ie": null, "ieStatus": "Data unavailable", "ieRaw": null, "ieUncertainty": null, "ieReference": null, "config": "[Rn]7s2 5f14 6d8 (predicted)", "shells": [ 2, 8, 18, 32, 32, 16, 2 ], "shellStatus": "Predicted configuration", "configSource": "PubChem", "state": "Bulk state unmeasured", "icon": "⚗", "kind": "Research", "use": "Darmstadtium is made only in research experiments.", "why": "Short lifetimes make many bulk-material measurements impossible.", "pubchemState": "Expected to be a Solid" }, { "number": 111, "symbol": "Rg", "name": "Roentgenium", "period": 7, "group": 11, "col": 11, "row": 7, "family": "Transition metal", "en": null, "radius": null, "ie": null, "ieStatus": "Data unavailable", "ieRaw": null, "ieUncertainty": null, "ieReference": null, "config": "[Rn]7s2 5f14 6d9 (predicted)", "shells": [ 2, 8, 18, 32, 32, 17, 2 ], "shellStatus": "Predicted configuration", "configSource": "PubChem", "state": "Bulk state unmeasured", "icon": "⚗", "kind": "Research", "use": "Roentgenium is studied through its production and radioactive decay.", "why": "A group position does not guarantee gold-like everyday behaviour.", "pubchemState": "Expected to be a Solid" }, { "number": 112, "symbol": "Cn", "name": "Copernicium", "period": 7, "group": 12, "col": 12, "row": 7, "family": "Transition metal", "en": null, "radius": null, "ie": null, "ieStatus": "Data unavailable", "ieRaw": null, "ieUncertainty": null, "ieReference": null, "config": "[Rn]7s2 5f14 6d10 (predicted)", "shells": [ 2, 8, 18, 32, 32, 18, 2 ], "shellStatus": "Predicted configuration", "configSource": "PubChem", "state": "Bulk state unmeasured", "icon": "⚗", "kind": "Research", "use": "Copernicium is studied in experiments on superheavy atoms.", "why": "Electrons in very heavy atoms require relativistic quantum calculations to predict their behaviour.", "pubchemState": "Expected to be a Solid", "statePrediction": { "phase": "Liquid", "status": "Theoretical prediction, not a bulk-phase measurement", "conditions": "Near room temperature under the ambient conditions discussed in the cited study. See the study for its calculation assumptions.", "source": "https://doi.org/10.1002/anie.201906966" } }, { "number": 113, "symbol": "Nh", "name": "Nihonium", "period": 7, "group": 13, "col": 13, "row": 7, "family": "Post-transition metal", "en": null, "radius": null, "ie": null, "ieStatus": "Data unavailable", "ieRaw": null, "ieUncertainty": null, "ieReference": null, "config": "[Rn]5f14 6d10 7s2 7p1 (predicted)", "shells": [ 2, 8, 18, 32, 32, 18, 3 ], "shellStatus": "Predicted configuration", "configSource": "PubChem", "state": "Bulk state unmeasured", "icon": "⚗", "kind": "Research", "use": "Nihonium is made in tiny numbers for research on superheavy nuclei.", "why": "Confirmed discovery does not mean all chemical properties have been measured.", "pubchemState": "Expected to be a Solid" }, { "number": 114, "symbol": "Fl", "name": "Flerovium", "period": 7, "group": 14, "col": 14, "row": 7, "family": "Post-transition metal", "en": null, "radius": null, "ie": null, "ieStatus": "Data unavailable", "ieRaw": null, "ieUncertainty": null, "ieReference": null, "config": "[Rn]7s2 7p2 5f14 6d10 (predicted)", "shells": [ 2, 8, 18, 32, 32, 18, 4 ], "shellStatus": "Predicted configuration", "configSource": "PubChem", "state": "Bulk state unmeasured", "icon": "⚗", "kind": "Research", "use": "Flerovium is studied in nuclear and atom-at-a-time chemistry experiments.", "why": "It helps test predictions about stability and electron behaviour.", "pubchemState": "Expected to be a Solid" }, { "number": 115, "symbol": "Mc", "name": "Moscovium", "period": 7, "group": 15, "col": 15, "row": 7, "family": "Post-transition metal", "en": null, "radius": null, "ie": null, "ieStatus": "Data unavailable", "ieRaw": null, "ieUncertainty": null, "ieReference": null, "config": "[Rn]7s2 7p3 5f14 6d10 (predicted)", "shells": [ 2, 8, 18, 32, 32, 18, 5 ], "shellStatus": "Predicted configuration", "configSource": "PubChem", "state": "Bulk state unmeasured", "icon": "⚗", "kind": "Research", "use": "Moscovium is produced only for scientific research.", "why": "Many of its chemical properties remain predictions rather than measurements.", "pubchemState": "Expected to be a Solid" }, { "number": 116, "symbol": "Lv", "name": "Livermorium", "period": 7, "group": 16, "col": 16, "row": 7, "family": "Post-transition metal", "en": null, "radius": null, "ie": null, "ieStatus": "Data unavailable", "ieRaw": null, "ieUncertainty": null, "ieReference": null, "config": "[Rn]7s2 7p4 5f14 6d10 (predicted)", "shells": [ 2, 8, 18, 32, 32, 18, 6 ], "shellStatus": "Predicted configuration", "configSource": "PubChem", "state": "Bulk state unmeasured", "icon": "⚗", "kind": "Research", "use": "Livermorium is made only in studies of superheavy nuclei.", "why": "Decay chains help scientists identify extremely short-lived elements.", "pubchemState": "Expected to be a Solid" }, { "number": 117, "symbol": "Ts", "name": "Tennessine", "period": 7, "group": 17, "col": 17, "row": 7, "family": "Halogen", "en": null, "radius": null, "ie": null, "ieStatus": "Data unavailable", "ieRaw": null, "ieUncertainty": null, "ieReference": null, "config": "[Rn]7s2 7p5 5f14 6d10 (predicted)", "shells": [ 2, 8, 18, 32, 32, 18, 7 ], "shellStatus": "Predicted configuration", "configSource": "PubChem", "state": "Bulk state unmeasured", "icon": "⚗", "kind": "Research", "use": "Tennessine is produced only for research; it has no everyday use.", "why": "Its group-17 position does not establish all the familiar halogen properties.", "pubchemState": "Expected to be a Solid" }, { "number": 118, "symbol": "Og", "name": "Oganesson", "period": 7, "group": 18, "col": 18, "row": 7, "family": "Noble gas", "en": null, "radius": null, "ie": null, "ieStatus": "Data unavailable", "ieRaw": null, "ieUncertainty": null, "ieReference": null, "config": "[Rn]7s2 7p6 5f14 6d10 (predicted)", "shells": [ 2, 8, 18, 32, 32, 18, 8 ], "shellStatus": "Predicted configuration", "configSource": "PubChem", "state": "Bulk state unmeasured", "icon": "⚗", "kind": "Research", "use": "Oganesson is made only for research in extremely small numbers.", "why": "Its group-18 position does not prove that it behaves like the lighter noble gases.", "pubchemState": "Expected to be a Gas", "statePrediction": { "phase": "Solid", "status": "Theoretical prediction, not a bulk-phase measurement", "conditions": "Near room temperature under the ambient conditions discussed in the cited study. See the study for its calculation assumptions.", "source": "https://doi.org/10.1002/anie.202011976" } } ]