Iron 26

Malleable, ductile, silvery metal; ferromagnetic; core of Earth; rusts easily.

| Selenium (Se) | 34 | Nonmetal to metalloid; photoconductive; essential in tiny amounts; red/gray forms. | Photocopiers, solar cells, glass decolorizer, dietary supplement.

| Ruthenium (Rh) | 44 | Rare, hard, silvery-white metal; part of the platinum group; resists wear. | Electrical contacts, wear-resistant alloys, chip resistors, catalysts. |

| Cesium (Cs) | 55 | Soft, gold-colored alkali metal; melts easily; most reactive non-radioactive metal. | Atomic clocks (defines the second), drilling fluids, photoelectric cells. | | Barium (Ba) | 56 | Soft, silvery alkaline earth metal; oxidizes easily; toxic compounds. | Drilling fluid (barite), X-ray contrast medium (barium swallow), fireworks (green). | | Lanthanum (La) | 57 | Soft, malleable, silvery-white rare-earth metal; tarnishes quickly in air. | Camera lenses, hydrogen storage batteries, flint lighters, petroleum refining. | | Cerium (Ce) | 58 | Soft, ductile, iron-gray rare-earth metal; most abundant of the lanthanides. | Catalytic converters, polishing powders (glass), flints for lighters, pigments. | | Praseodymium (Pr) | 59 | Soft, silvery, malleable rare-earth metal; forms a green oxide coating. | Strong magnets (with neodymium), aircraft engines, colored glass/ceramics (yellow). | | Neodymium (Nd) | 60 | Silvery-white rare-earth metal; forms strong permanent magnets (NdFeB). | Powerful permanent magnets (headphones, motors, wind turbines), lasers. | | Promethium (Pm) | 61 | Radioactive rare-earth metal; its salts glow pale blue/green in the dark. | Nuclear batteries (pacemakers, spacecraft), luminous paint, thickness gauges. | | Samarium (Sm) | 62 | Hard, silvery rare-earth metal; forms strong permanent magnets (with cobalt). | Strong magnets (SmCo), nuclear reactor control rods, cancer treatment. | | Europium (Eu) | 63 | Soft, silvery rare-earth metal; the most reactive lanthanide. | Red and blue phosphors in TV/phone screens, fluorescent lamps, lasers. | | Gadolinium (Gd) | 64 | Silvery-white, malleable rare-earth metal; strongly ferromagnetic near room temp. | MRI contrast agent, neutron absorber in reactors, data storage, magnets. | | Terbium (Tb) | 65 | Silvery-gray rare-earth metal; soft, malleable, and ductile. | Green phosphors in TV screens/lamps, solid-state devices, fuel cells. | | Dysprosium (Dy) | 66 | Bright, silvery rare-earth metal; soft enough to cut with a knife. | Additive to neodymium magnets (for high-temp stability), lasers, nuclear reactors. | | Holmium (Ho) | 67 | Relatively soft, silvery rare-earth metal; has the highest magnetic strength. | Powerful magnets, nuclear control rods, colorants for glass/cubic zirconia. | | Erbium (Er) | 68 | Soft, malleable, silvery rare-earth metal; gives pink color to glass/salts. | Fiber-optic cable amplifiers (internet), pink glass/crystal, laser surgery. | | Thulium (Tm) | 69 | Silvery-gray, soft rare-earth metal; the rarest naturally occurring lanthanide. | Portable X-ray machines, lasers (surgery), high-temperature superconductors. | | Ytterbium (Yb) | 70 | Bright, silvery, soft rare-earth metal; somewhat reactive. | Stainless steel alloy, pressure sensors, lasers, atomic clocks. | | Lutetium (Lu) | 71 | Hard, dense, silvery-white rare-earth metal; the heaviest and hardest lanthanide. | Petroleum cracking catalyst, LED light bulbs, cancer therapy, positron tomography. | | Hafnium (Hf) | 72 | Lustrous, silvery, ductile metal; excellent neutron absorber. | Nuclear reactor control rods, microprocessor chips, plasma cutting tips. | | Tantalum (Ta) | 73 | Hard, blue-gray, lustrous metal; highly corrosion-resistant; biocompatible. | Capacitors for electronics (phones, laptops), surgical implants, cutting tools. | | Tungsten (W) | 74 | Hard, steel-gray to white metal; highest melting point of all metals. | Filaments in lights, carbide cutting tools, X-ray targets, military alloys. | | Rhenium (Re) | 75 | Silvery-white, heavy metal; one of the highest melting points; very rare. | Superalloys for jet engine blades, catalysts for petroleum refining, thermocouples. | | Osmium (Os) | 76 | Bluish-white, hard, brittle metal; the densest naturally occurring element. | Hard alloys for pen tips, electrical contacts, instrument pivots (with iridium). | | Iridium (Ir) | 77 | Very hard, brittle, silvery-white metal; extremely corrosion-resistant; dense. | Spark plugs, crucibles for crystal growth, standard meter/kilogram prototypes. | | Platinum (Pt) | 78 | Dense, malleable, silvery-white precious metal; highly corrosion-resistant. | Catalytic converters, jewelry, lab equipment, electrodes, cancer drugs. | | Gold (Au) | 79 | Dense, soft, malleable, yellow precious metal; most ductile; doesn’t tarnish. | Jewelry, currency, electronics (connectors), dentistry, investment. | | Mercury (Hg) | 80 | Silvery, liquid metal at room temp; toxic; forms amalgams with metals. | Thermometers, barometers, electrical switches, dental amalgam, gold mining. | | Thallium (Tl) | 81 | Very soft, malleable, silvery metal that tarnishes gray; highly toxic. | Rodent poison (historically), infrared optics, superconductors, low-melting glass. | | Lead (Pb) | 82 | Dense, soft, malleable, bluish-gray metal; toxic; resists corrosion. | Car batteries, radiation shielding, solder, weights, stained glass (historically). | | Bismuth (Bi) | 83 | Brittle, silvery-white with pink tinge; diamagnetic; low toxicity; expands on freezing. | Pepto-Bismol, low-melting alloys (fire sprinklers), cosmetics, replacement for lead. | | Polonium (Po) | 84 | Radioactive, silvery-gray metal; highly toxic and volatile. | Antistatic devices (brushes), heat source in space probes, neutron source. | | Francium (Fr) | 87 | Radioactive alkali metal; extremely rare and unstable. | No practical uses; only for scientific research. |

| Radium (Ra) | 88 | Radioactive, silvery-white alkaline earth metal; glows faintly in the dark. | Cancer radiotherapy (historically), luminous paint (watches, aircraft dials). | | Actinium (Ac) | 89 | Silvery-white, radioactive metal; glows blue in the dark due to ionization. | Neutron source, radioimmunotherapy agents (targeted cancer treatment). | | Thorium (Th) | 90 | Silvery, radioactive metal; more abundant than uranium. | Nuclear fuel (potential), gas lantern mantles, alloying agent, camera lenses. | | Protactinium (Pa) | 91 | Dense, silvery-gray, radioactive metal; highly toxic and scarce. | No significant uses; scientific research only. | | Uranium (U) | 92 | Dense, silvery-gray, radioactive metal; the main fuel for nuclear reactors. | Nuclear fuel (power generation), military armor/ammunition, dating rocks. | | Neptunium (Np) | 93 | Silvery, radioactive, ductile metal; first transuranium element synthesized. | Precursor for Plutonium-238 (used in spacecraft batteries), scientific research. | | Plutonium (Pu) | 94 | Silvery-white, radioactive, pyrophoric metal; key for nuclear weapons. | Nuclear weapons fuel, radioisotope thermoelectric generators (spacecraft). | | Americium (Am) | 95 | Silvery-white, radioactive metal; widely used in household detectors. | Smoke detectors (ionization type), neutron sources, thickness gauges. | | Curium (Cm) | 96 | Silvery, hard, dense, radioactive metal; glows in the dark. | Alpha particle source for spectrometers, power source in space probes. | | Berkelium (Bk) | 97 | Silvery-white, radioactive metal; relatively soft and paramagnetic. | Synthesis of heavier elements (e.g., Tennessine), scientific research. | | Californium (Cf) | 98 | Silvery-white, radioactive metal; strong neutron emitter. | Neutron startup rods for reactors, moisture gauges, cancer treatment. |