[ { "number": 1, "symbol": "H", "name": "Hydrogen", "atomic_mass": 1.008, "category": "Nonmetal", "phase": "Gas", "block": "s", "period": 1, "group": 1, "electron_config": "1s1", "electronegativity": 2.2, "melting_point": 14.01, "boiling_point": 20.28, "density": 0.00009, "atomic_radius": 53, "ionization_energy": 1312, "electron_affinity": -73, "oxidation_states": "-1, +1", "discovered_by": "Henry Cavendish", "discovery_year": 1766 }, { "number": 2, "symbol": "He", "name": "Helium", "atomic_mass": 4.003, "category": "Noble Gas", "phase": "Gas", "block": "s", "period": 1, "group": 18, "electron_config": "1s2", "electronegativity": "N/A", "melting_point": 0.95, "boiling_point": 4.22, "density": 0.000179, "atomic_radius": 31, "ionization_energy": 2372.3, "electron_affinity": 0, "oxidation_states": "0", "discovered_by": "Pierre Janssen", "discovery_year": 1868 }, { "number": 3, "symbol": "Li", "name": "Lithium", "atomic_mass": 6.941, "category": "Alkali Metal", "phase": "Solid", "block": "s", "period": 2, "group": 1, "electron_config": "[He] 2s1", "electronegativity": 0.98, "melting_point": 453.69, "boiling_point": 1615, "density": 0.534, "atomic_radius": 167, "ionization_energy": 520.2, "electron_affinity": -60, "oxidation_states": "+1", "discovered_by": "Johan August Arfwedson", "discovery_year": 1817 }, { "number": 4, "symbol": "Be", "name": "Beryllium", "atomic_mass": 9.012, "category": "Alkaline Earth", "phase": "Solid", "block": "s", "period": 2, "group": 2, "electron_config": "[He] 2s2", "electronegativity": 1.57, "melting_point": 1560, "boiling_point": 2742, "density": 1.85, "atomic_radius": 112, "ionization_energy": 899.5, "electron_affinity": 0, "oxidation_states": "+2", "discovered_by": "Louis Nicolas Vauquelin", "discovery_year": 1798 }, { "number": 5, "symbol": "B", "name": "Boron", "atomic_mass": 10.81, "category": "Metalloid", "phase": "Solid", "block": "p", "period": 2, "group": 13, "electron_config": "[He] 2s2 2p1", "electronegativity": 2.04, "melting_point": 2349, "boiling_point": 4200, "density": 2.34, "atomic_radius": 87, "ionization_energy": 800.6, "electron_affinity": -27, "oxidation_states": "+3", "discovered_by": "Joseph Louis Gay-Lussac", "discovery_year": 1808 }, { "number": 6, "symbol": "C", "name": "Carbon", "atomic_mass": 12.011, "category": "Nonmetal", "phase": "Solid", "block": "p", "period": 2, "group": 14, "electron_config": "[He] 2s2 2p2", "electronegativity": 2.55, "melting_point": 3823, "boiling_point": 4098, "density": 2.267, "atomic_radius": 77, "ionization_energy": 1086.5, "electron_affinity": -154, "oxidation_states": "-4, +4", "discovered_by": "Ancient", "discovery_year": "Ancient" }, { "number": 7, "symbol": "N", "name": "Nitrogen", "atomic_mass": 14.007, "category": "Nonmetal", "phase": "Gas", "block": "p", "period": 2, "group": 15, "electron_config": "[He] 2s2 2p3", "electronegativity": 3.04, "melting_point": 63.15, "boiling_point": 77.36, "density": 0.001251, "atomic_radius": 75, "ionization_energy": 1402.3, "electron_affinity": -7, "oxidation_states": "-3, +3, +5", "discovered_by": "Daniel Rutherford", "discovery_year": 1772 }, { "number": 8, "symbol": "O", "name": "Oxygen", "atomic_mass": 15.999, "category": "Nonmetal", "phase": "Gas", "block": "p", "period": 2, "group": 16, "electron_config": "[He] 2s2 2p4", "electronegativity": 3.44, "melting_point": 54.36, "boiling_point": 90.2, "density": 0.001429, "atomic_radius": 73, "ionization_energy": 1313.9, "electron_affinity": -141, "oxidation_states": "-2", "discovered_by": "Carl Wilhelm Scheele", "discovery_year": 1774 }, { "number": 9, "symbol": "F", "name": "Fluorine", "atomic_mass": 18.998, "category": "Halogen", "phase": "Gas", "block": "p", "period": 2, "group": 17, "electron_config": "[He] 2s2 2p5", "electronegativity": 3.98, "melting_point": 53.53, "boiling_point": 85.03, "density": 0.001696, "atomic_radius": 71, "ionization_energy": 1681, "electron_affinity": -328, "oxidation_states": "-1", "discovered_by": "Henri Moissan", "discovery_year": 1886 }, { "number": 10, "symbol": "Ne", "name": "Neon", "atomic_mass": 20.18, "category": "Noble Gas", "phase": "Gas", "block": "p", "period": 2, "group": 18, "electron_config": "[He] 2s2 2p6", "electronegativity": "N/A", "melting_point": 24.56, "boiling_point": 27.07, "density": 0.0009, "atomic_radius": 38, "ionization_energy": 2080.7, "electron_affinity": 0, "oxidation_states": "0", "discovered_by": "William Ramsay", "discovery_year": 1898 }, { "number": 11, "symbol": "Na", "name": "Sodium", "atomic_mass": 22.99, "category": "Alkali Metal", "phase": "Solid", "block": "s", "period": 3, "group": 1, "electron_config": "[Ne] 3s1", "electronegativity": 0.93, "melting_point": 370.87, "boiling_point": 1156, "density": 0.971, "atomic_radius": 190, "ionization_energy": 495.8, "electron_affinity": -53, "oxidation_states": "+1", "discovered_by": "Humphry Davy", "discovery_year": 1807 }, { "number": 12, "symbol": "Mg", "name": "Magnesium", "atomic_mass": 24.305, "category": "Alkaline Earth", "phase": "Solid", "block": "s", "period": 3, "group": 2, "electron_config": "[Ne] 3s2", "electronegativity": 1.31, "melting_point": 923, "boiling_point": 1363, "density": 1.738, "atomic_radius": 145, "ionization_energy": 737.7, "electron_affinity": 0, "oxidation_states": "+2", "discovered_by": "Joseph Black", "discovery_year": 1755 }, { "number": 13, "symbol": "Al", "name": "Aluminum", "atomic_mass": 26.982, "category": "Post-Transition", "phase": "Solid", "block": "p", "period": 3, "group": 13, "electron_config": "[Ne] 3s2 3p1", "electronegativity": 1.61, "melting_point": 933.47, "boiling_point": 2792, "density": 2.698, "atomic_radius": 125, "ionization_energy": 577.5, "electron_affinity": -43, "oxidation_states": "+3", "discovered_by": "Hans Christian Oersted", "discovery_year": 1825 }, { "number": 14, "symbol": "Si", "name": "Silicon", "atomic_mass": 28.086, "category": "Metalloid", "phase": "Solid", "block": "p", "period": 3, "group": 14, "electron_config": "[Ne] 3s2 3p2", "electronegativity": 1.9, "melting_point": 1687, "boiling_point": 3538, "density": 2.3296, "atomic_radius": 111, "ionization_energy": 786.5, "electron_affinity": -134, "oxidation_states": "-4, +4", "discovered_by": "Jons Jacob Berzelius", "discovery_year": 1824 }, { "number": 15, "symbol": "P", "name": "Phosphorus", "atomic_mass": 30.974, "category": "Nonmetal", "phase": "Solid", "block": "p", "period": 3, "group": 15, "electron_config": "[Ne] 3s2 3p3", "electronegativity": 2.19, "melting_point": 317.3, "boiling_point": 550, "density": 1.82, "atomic_radius": 106, "ionization_energy": 1011.8, "electron_affinity": -72, "oxidation_states": "-3, +3, +5", "discovered_by": "Hennig Brand", "discovery_year": 1669 }, { "number": 16, "symbol": "S", "name": "Sulfur", "atomic_mass": 32.06, "category": "Nonmetal", "phase": "Solid", "block": "p", "period": 3, "group": 16, "electron_config": "[Ne] 3s2 3p4", "electronegativity": 2.58, "melting_point": 388.36, "boiling_point": 717.87, "density": 2.067, "atomic_radius": 102, "ionization_energy": 999.6, "electron_affinity": -200, "oxidation_states": "-2, +4, +6", "discovered_by": "Ancient", "discovery_year": "Ancient" }, { "number": 17, "symbol": "Cl", "name": "Chlorine", "atomic_mass": 35.45, "category": "Halogen", "phase": "Gas", "block": "p", "period": 3, "group": 17, "electron_config": "[Ne] 3s2 3p5", "electronegativity": 3.16, "melting_point": 171.6, "boiling_point": 239.11, "density": 0.003214, "atomic_radius": 99, "ionization_energy": 1251.2, "electron_affinity": -349, "oxidation_states": "-1, +1, +3, +5, +7", "discovered_by": "Carl Wilhelm Scheele", "discovery_year": 1774 }, { "number": 18, "symbol": "Ar", "name": "Argon", "atomic_mass": 39.948, "category": "Noble Gas", "phase": "Gas", "block": "p", "period": 3, "group": 18, "electron_config": "[Ne] 3s2 3p6", "electronegativity": "N/A", "melting_point": 83.8, "boiling_point": 87.3, "density": 0.001784, "atomic_radius": 71, "ionization_energy": 1520.6, "electron_affinity": 0, "oxidation_states": "0", "discovered_by": "Lord Rayleigh", "discovery_year": 1894 }, { "number": 19, "symbol": "K", "name": "Potassium", "atomic_mass": 39.098, "category": "Alkali Metal", "phase": "Solid", "block": "s", "period": 4, "group": 1, "electron_config": "[Ar] 4s1", "electronegativity": 0.82, "melting_point": 336.53, "boiling_point": 1032, "density": 0.862, "atomic_radius": 243, "ionization_energy": 418.8, "electron_affinity": -48, "oxidation_states": "+1", "discovered_by": "Humphry Davy", "discovery_year": 1807 }, { "number": 20, "symbol": "Ca", "name": "Calcium", "atomic_mass": 40.078, "category": "Alkaline Earth", "phase": "Solid", "block": "s", "period": 4, "group": 2, "electron_config": "[Ar] 4s2", "electronegativity": 1, "melting_point": 1115, "boiling_point": 1757, "density": 1.55, "atomic_radius": 194, "ionization_energy": 589.8, "electron_affinity": -2, "oxidation_states": "+2", "discovered_by": "Humphry Davy", "discovery_year": 1808 }, { "number": 21, "symbol": "Sc", "name": "Scandium", "atomic_mass": 44.956, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 4, "group": 3, "electron_config": "[Ar] 3d1 4s2", "electronegativity": 1.36, "melting_point": 1814, "boiling_point": 3109, "density": 2.989, "atomic_radius": 184, "ionization_energy": 633.1, "electron_affinity": -18, "oxidation_states": "+3", "discovered_by": "Lars Fredrik Nilson", "discovery_year": 1879 }, { "number": 22, "symbol": "Ti", "name": "Titanium", "atomic_mass": 47.867, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 4, "group": 4, "electron_config": "[Ar] 3d2 4s2", "electronegativity": 1.54, "melting_point": 1941, "boiling_point": 3560, "density": 4.54, "atomic_radius": 176, "ionization_energy": 658.8, "electron_affinity": -8, "oxidation_states": "+2, +3, +4", "discovered_by": "William Gregor", "discovery_year": 1791 }, { "number": 23, "symbol": "V", "name": "Vanadium", "atomic_mass": 50.942, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 4, "group": 5, "electron_config": "[Ar] 3d3 4s2", "electronegativity": 1.63, "melting_point": 2183, "boiling_point": 3680, "density": 6.11, "atomic_radius": 171, "ionization_energy": 650.9, "electron_affinity": -51, "oxidation_states": "+2, +3, +4, +5", "discovered_by": "Andres Manuel del Rio", "discovery_year": 1801 }, { "number": 24, "symbol": "Cr", "name": "Chromium", "atomic_mass": 51.996, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 4, "group": 6, "electron_config": "[Ar] 3d5 4s1", "electronegativity": 1.66, "melting_point": 2180, "boiling_point": 2944, "density": 7.15, "atomic_radius": 166, "ionization_energy": 652.9, "electron_affinity": -64, "oxidation_states": "+2, +3, +6", "discovered_by": "Louis Nicolas Vauquelin", "discovery_year": 1797 }, { "number": 25, "symbol": "Mn", "name": "Manganese", "atomic_mass": 54.938, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 4, "group": 7, "electron_config": "[Ar] 3d5 4s2", "electronegativity": 1.55, "melting_point": 1519, "boiling_point": 2334, "density": 7.44, "atomic_radius": 161, "ionization_energy": 717.3, "electron_affinity": 0, "oxidation_states": "+2, +4, +7", "discovered_by": "Johan Gottlieb Gahn", "discovery_year": 1774 }, { "number": 26, "symbol": "Fe", "name": "Iron", "atomic_mass": 55.845, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 4, "group": 8, "electron_config": "[Ar] 3d6 4s2", "electronegativity": 1.83, "melting_point": 1811, "boiling_point": 3134, "density": 7.874, "atomic_radius": 156, "ionization_energy": 762.5, "electron_affinity": -16, "oxidation_states": "+2, +3", "discovered_by": "Ancient", "discovery_year": "Ancient" }, { "number": 27, "symbol": "Co", "name": "Cobalt", "atomic_mass": 58.933, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 4, "group": 9, "electron_config": "[Ar] 3d7 4s2", "electronegativity": 1.88, "melting_point": 1768, "boiling_point": 3200, "density": 8.9, "atomic_radius": 152, "ionization_energy": 760.4, "electron_affinity": -64, "oxidation_states": "+2, +3", "discovered_by": "Georg Brandt", "discovery_year": 1735 }, { "number": 28, "symbol": "Ni", "name": "Nickel", "atomic_mass": 58.693, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 4, "group": 10, "electron_config": "[Ar] 3d8 4s2", "electronegativity": 1.91, "melting_point": 1728, "boiling_point": 3186, "density": 8.912, "atomic_radius": 149, "ionization_energy": 737.1, "electron_affinity": -112, "oxidation_states": "+2, +3", "discovered_by": "Axel Fredrik Cronstedt", "discovery_year": 1751 }, { "number": 29, "symbol": "Cu", "name": "Copper", "atomic_mass": 63.546, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 4, "group": 11, "electron_config": "[Ar] 3d10 4s1", "electronegativity": 1.9, "melting_point": 1357.77, "boiling_point": 2835, "density": 8.96, "atomic_radius": 145, "ionization_energy": 745.5, "electron_affinity": -119, "oxidation_states": "+1, +2", "discovered_by": "Ancient", "discovery_year": "Ancient" }, { "number": 30, "symbol": "Zn", "name": "Zinc", "atomic_mass": 65.38, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 4, "group": 12, "electron_config": "[Ar] 3d10 4s2", "electronegativity": 1.65, "melting_point": 692.68, "boiling_point": 1180, "density": 7.134, "atomic_radius": 142, "ionization_energy": 906.4, "electron_affinity": 0, "oxidation_states": "+2", "discovered_by": "Ancient", "discovery_year": "Ancient" }, { "number": 31, "symbol": "Ga", "name": "Gallium", "atomic_mass": 69.723, "category": "Post-Transition", "phase": "Solid", "block": "p", "period": 4, "group": 13, "electron_config": "[Ar] 3d10 4s2 4p1", "electronegativity": 1.81, "melting_point": 302.91, "boiling_point": 2477, "density": 5.907, "atomic_radius": 136, "ionization_energy": 578.8, "electron_affinity": -29, "oxidation_states": "+3", "discovered_by": "Paul Emile Lecoq de Boisbaudran", "discovery_year": 1875 }, { "number": 32, "symbol": "Ge", "name": "Germanium", "atomic_mass": 72.63, "category": "Metalloid", "phase": "Solid", "block": "p", "period": 4, "group": 14, "electron_config": "[Ar] 3d10 4s2 4p2", "electronegativity": 2.01, "melting_point": 1211.4, "boiling_point": 3106, "density": 5.323, "atomic_radius": 125, "ionization_energy": 762.2, "electron_affinity": -119, "oxidation_states": "+2, +4", "discovered_by": "Clemens Winkler", "discovery_year": 1886 }, { "number": 33, "symbol": "As", "name": "Arsenic", "atomic_mass": 74.922, "category": "Metalloid", "phase": "Solid", "block": "p", "period": 4, "group": 15, "electron_config": "[Ar] 3d10 4s2 4p3", "electronegativity": 2.18, "melting_point": 1090, "boiling_point": 887, "density": 5.776, "atomic_radius": 114, "ionization_energy": 947, "electron_affinity": -78, "oxidation_states": "-3, +3, +5", "discovered_by": "Ancient", "discovery_year": "Ancient" }, { "number": 34, "symbol": "Se", "name": "Selenium", "atomic_mass": 78.971, "category": "Nonmetal", "phase": "Solid", "block": "p", "period": 4, "group": 16, "electron_config": "[Ar] 3d10 4s2 4p4", "electronegativity": 2.55, "melting_point": 494, "boiling_point": 958, "density": 4.809, "atomic_radius": 103, "ionization_energy": 941, "electron_affinity": -195, "oxidation_states": "-2, +4, +6", "discovered_by": "Jons Jacob Berzelius", "discovery_year": 1817 }, { "number": 35, "symbol": "Br", "name": "Bromine", "atomic_mass": 79.904, "category": "Halogen", "phase": "Liquid", "block": "p", "period": 4, "group": 17, "electron_config": "[Ar] 3d10 4s2 4p5", "electronegativity": 2.96, "melting_point": 265.8, "boiling_point": 332, "density": 3.122, "atomic_radius": 94, "ionization_energy": 1139.9, "electron_affinity": -325, "oxidation_states": "-1, +1, +3, +5", "discovered_by": "Antoine Jerome Balard", "discovery_year": 1826 }, { "number": 36, "symbol": "Kr", "name": "Krypton", "atomic_mass": 83.798, "category": "Noble Gas", "phase": "Gas", "block": "p", "period": 4, "group": 18, "electron_config": "[Ar] 3d10 4s2 4p6", "electronegativity": 3, "melting_point": 115.79, "boiling_point": 119.93, "density": 0.003749, "atomic_radius": 88, "ionization_energy": 1350.8, "electron_affinity": 0, "oxidation_states": "0, +2", "discovered_by": "William Ramsay", "discovery_year": 1898 }, { "number": 37, "symbol": "Rb", "name": "Rubidium", "atomic_mass": 85.468, "category": "Alkali Metal", "phase": "Solid", "block": "s", "period": 5, "group": 1, "electron_config": "[Kr] 5s1", "electronegativity": 0.82, "melting_point": 312.46, "boiling_point": 961, "density": 1.532, "atomic_radius": 265, "ionization_energy": 403, "electron_affinity": -47, "oxidation_states": "+1", "discovered_by": "Robert Bunsen", "discovery_year": 1861 }, { "number": 38, "symbol": "Sr", "name": "Strontium", "atomic_mass": 87.62, "category": "Alkaline Earth", "phase": "Solid", "block": "s", "period": 5, "group": 2, "electron_config": "[Kr] 5s2", "electronegativity": 0.95, "melting_point": 1050, "boiling_point": 1655, "density": 2.64, "atomic_radius": 219, "ionization_energy": 549.5, "electron_affinity": -5, "oxidation_states": "+2", "discovered_by": "William Cruickshank", "discovery_year": 1790 }, { "number": 39, "symbol": "Y", "name": "Yttrium", "atomic_mass": 88.906, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 5, "group": 3, "electron_config": "[Kr] 4d1 5s2", "electronegativity": 1.22, "melting_point": 1799, "boiling_point": 3609, "density": 4.469, "atomic_radius": 212, "ionization_energy": 600, "electron_affinity": -30, "oxidation_states": "+3", "discovered_by": "Johan Gadolin", "discovery_year": 1794 }, { "number": 40, "symbol": "Zr", "name": "Zirconium", "atomic_mass": 91.224, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 5, "group": 4, "electron_config": "[Kr] 4d2 5s2", "electronegativity": 1.33, "melting_point": 2128, "boiling_point": 4682, "density": 6.506, "atomic_radius": 206, "ionization_energy": 640.1, "electron_affinity": -41, "oxidation_states": "+4", "discovered_by": "Martin Heinrich Klaproth", "discovery_year": 1789 }, { "number": 41, "symbol": "Nb", "name": "Niobium", "atomic_mass": 92.906, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 5, "group": 5, "electron_config": "[Kr] 4d4 5s1", "electronegativity": 1.6, "melting_point": 2750, "boiling_point": 5017, "density": 8.57, "atomic_radius": 198, "ionization_energy": 652.1, "electron_affinity": -86, "oxidation_states": "+3, +5", "discovered_by": "Charles Hatchett", "discovery_year": 1801 }, { "number": 42, "symbol": "Mo", "name": "Molybdenum", "atomic_mass": 95.95, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 5, "group": 6, "electron_config": "[Kr] 4d5 5s1", "electronegativity": 2.16, "melting_point": 2896, "boiling_point": 4912, "density": 10.22, "atomic_radius": 190, "ionization_energy": 684.3, "electron_affinity": -72, "oxidation_states": "+4, +6", "discovered_by": "Carl Wilhelm Scheele", "discovery_year": 1778 }, { "number": 43, "symbol": "Tc", "name": "Technetium", "atomic_mass": 98, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 5, "group": 7, "electron_config": "[Kr] 4d5 5s2", "electronegativity": 1.9, "melting_point": 2430, "boiling_point": 4538, "density": 11.5, "atomic_radius": 183, "ionization_energy": 702, "electron_affinity": -53, "oxidation_states": "+4, +7", "discovered_by": "Emilio Segre", "discovery_year": 1937 }, { "number": 44, "symbol": "Ru", "name": "Ruthenium", "atomic_mass": 101.07, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 5, "group": 8, "electron_config": "[Kr] 4d7 5s1", "electronegativity": 2.2, "melting_point": 2607, "boiling_point": 4423, "density": 12.37, "atomic_radius": 178, "ionization_energy": 710.2, "electron_affinity": -101, "oxidation_states": "+3, +4", "discovered_by": "Karl Ernst Claus", "discovery_year": 1844 }, { "number": 45, "symbol": "Rh", "name": "Rhodium", "atomic_mass": 102.91, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 5, "group": 9, "electron_config": "[Kr] 4d8 5s1", "electronegativity": 2.28, "melting_point": 2237, "boiling_point": 3968, "density": 12.41, "atomic_radius": 173, "ionization_energy": 719.7, "electron_affinity": -110, "oxidation_states": "+3", "discovered_by": "William Hyde Wollaston", "discovery_year": 1803 }, { "number": 46, "symbol": "Pd", "name": "Palladium", "atomic_mass": 106.42, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 5, "group": 10, "electron_config": "[Kr] 4d10", "electronegativity": 2.2, "melting_point": 1828.05, "boiling_point": 3236, "density": 12.02, "atomic_radius": 169, "ionization_energy": 804.4, "electron_affinity": -54, "oxidation_states": "+2, +4", "discovered_by": "William Hyde Wollaston", "discovery_year": 1803 }, { "number": 47, "symbol": "Ag", "name": "Silver", "atomic_mass": 107.87, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 5, "group": 11, "electron_config": "[Kr] 4d10 5s1", "electronegativity": 1.93, "melting_point": 1234.93, "boiling_point": 2435, "density": 10.501, "atomic_radius": 165, "ionization_energy": 731, "electron_affinity": -126, "oxidation_states": "+1", "discovered_by": "Ancient", "discovery_year": "Ancient" }, { "number": 48, "symbol": "Cd", "name": "Cadmium", "atomic_mass": 112.41, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 5, "group": 12, "electron_config": "[Kr] 4d10 5s2", "electronegativity": 1.69, "melting_point": 594.22, "boiling_point": 1040, "density": 8.69, "atomic_radius": 161, "ionization_energy": 867.8, "electron_affinity": 0, "oxidation_states": "+2", "discovered_by": "Karl Samuel Leberecht Hermann", "discovery_year": 1817 }, { "number": 49, "symbol": "In", "name": "Indium", "atomic_mass": 114.82, "category": "Post-Transition", "phase": "Solid", "block": "p", "period": 5, "group": 13, "electron_config": "[Kr] 4d10 5s2 5p1", "electronegativity": 1.78, "melting_point": 429.75, "boiling_point": 2345, "density": 7.31, "atomic_radius": 156, "ionization_energy": 558.3, "electron_affinity": -29, "oxidation_states": "+3", "discovered_by": "Ferdinand Reich", "discovery_year": 1863 }, { "number": 50, "symbol": "Sn", "name": "Tin", "atomic_mass": 118.71, "category": "Post-Transition", "phase": "Solid", "block": "p", "period": 5, "group": 14, "electron_config": "[Kr] 4d10 5s2 5p2", "electronegativity": 1.96, "melting_point": 505.08, "boiling_point": 2875, "density": 7.287, "atomic_radius": 145, "ionization_energy": 708.6, "electron_affinity": -107, "oxidation_states": "+2, +4", "discovered_by": "Ancient", "discovery_year": "Ancient" }, { "number": 51, "symbol": "Sb", "name": "Antimony", "atomic_mass": 121.76, "category": "Metalloid", "phase": "Solid", "block": "p", "period": 5, "group": 15, "electron_config": "[Kr] 4d10 5s2 5p3", "electronegativity": 2.05, "melting_point": 903.78, "boiling_point": 1860, "density": 6.685, "atomic_radius": 133, "ionization_energy": 834, "electron_affinity": -103, "oxidation_states": "-3, +3, +5", "discovered_by": "Ancient", "discovery_year": "Ancient" }, { "number": 52, "symbol": "Te", "name": "Tellurium", "atomic_mass": 127.6, "category": "Metalloid", "phase": "Solid", "block": "p", "period": 5, "group": 16, "electron_config": "[Kr] 4d10 5s2 5p4", "electronegativity": 2.1, "melting_point": 722.66, "boiling_point": 1261, "density": 6.232, "atomic_radius": 123, "ionization_energy": 869.3, "electron_affinity": -190, "oxidation_states": "-2, +4, +6", "discovered_by": "Franz-Joseph Muller von Reichenstein", "discovery_year": 1783 }, { "number": 53, "symbol": "I", "name": "Iodine", "atomic_mass": 126.9, "category": "Halogen", "phase": "Solid", "block": "p", "period": 5, "group": 17, "electron_config": "[Kr] 4d10 5s2 5p5", "electronegativity": 2.66, "melting_point": 386.85, "boiling_point": 457.4, "density": 4.93, "atomic_radius": 115, "ionization_energy": 1008.4, "electron_affinity": -295, "oxidation_states": "-1, +1, +5, +7", "discovered_by": "Bernard Courtois", "discovery_year": 1811 }, { "number": 54, "symbol": "Xe", "name": "Xenon", "atomic_mass": 131.29, "category": "Noble Gas", "phase": "Gas", "block": "p", "period": 5, "group": 18, "electron_config": "[Kr] 4d10 5s2 5p6", "electronegativity": 2.6, "melting_point": 161.4, "boiling_point": 165.03, "density": 0.005887, "atomic_radius": 108, "ionization_energy": 1170.4, "electron_affinity": 0, "oxidation_states": "0, +2, +4, +6", "discovered_by": "William Ramsay", "discovery_year": 1898 }, { "number": 55, "symbol": "Cs", "name": "Cesium", "atomic_mass": 132.91, "category": "Alkali Metal", "phase": "Solid", "block": "s", "period": 6, "group": 1, "electron_config": "[Xe] 6s1", "electronegativity": 0.79, "melting_point": 301.59, "boiling_point": 944, "density": 1.873, "atomic_radius": 298, "ionization_energy": 375.7, "electron_affinity": -46, "oxidation_states": "+1", "discovered_by": "Robert Bunsen", "discovery_year": 1860 }, { "number": 56, "symbol": "Ba", "name": "Barium", "atomic_mass": 137.33, "category": "Alkaline Earth", "phase": "Solid", "block": "s", "period": 6, "group": 2, "electron_config": "[Xe] 6s2", "electronegativity": 0.89, "melting_point": 1000, "boiling_point": 2170, "density": 3.594, "atomic_radius": 253, "ionization_energy": 502.9, "electron_affinity": -14, "oxidation_states": "+2", "discovered_by": "Carl Wilhelm Scheele", "discovery_year": 1772 }, { "number": 57, "symbol": "La", "name": "Lanthanum", "atomic_mass": 138.91, "category": "Lanthanide", "phase": "Solid", "block": "f", "period": 6, "group": 3, "electron_config": "[Xe] 5d1 6s2", "electronegativity": 1.1, "melting_point": 1193, "boiling_point": 3737, "density": 6.145, "atomic_radius": 195, "ionization_energy": 538.1, "electron_affinity": -48, "oxidation_states": "+3", "discovered_by": "Carl Gustaf Mosander", "discovery_year": 1839 }, { "number": 58, "symbol": "Ce", "name": "Cerium", "atomic_mass": 140.12, "category": "Lanthanide", "phase": "Solid", "block": "f", "period": 6, "group": "N/A", "electron_config": "[Xe] 4f1 5d1 6s2", "electronegativity": 1.12, "melting_point": 1068, "boiling_point": 3716, "density": 6.77, "atomic_radius": 185, "ionization_energy": 534.4, "electron_affinity": -50, "oxidation_states": "+3, +4", "discovered_by": "Jons Jacob Berzelius", "discovery_year": 1803 }, { "number": 59, "symbol": "Pr", "name": "Praseodymium", "atomic_mass": 140.91, "category": "Lanthanide", "phase": "Solid", "block": "f", "period": 6, "group": "N/A", "electron_config": "[Xe] 4f3 6s2", "electronegativity": 1.13, "melting_point": 1208, "boiling_point": 3793, "density": 6.773, "atomic_radius": 185, "ionization_energy": 527, "electron_affinity": -50, "oxidation_states": "+3", "discovered_by": "Carl Auer von Welsbach", "discovery_year": 1885 }, { "number": 60, "symbol": "Nd", "name": "Neodymium", "atomic_mass": 144.24, "category": "Lanthanide", "phase": "Solid", "block": "f", "period": 6, "group": "N/A", "electron_config": "[Xe] 4f4 6s2", "electronegativity": 1.14, "melting_point": 1297, "boiling_point": 3347, "density": 7.007, "atomic_radius": 185, "ionization_energy": 533.1, "electron_affinity": -50, "oxidation_states": "+3", "discovered_by": "Carl Auer von Welsbach", "discovery_year": 1885 }, { "number": 61, "symbol": "Pm", "name": "Promethium", "atomic_mass": 145, "category": "Lanthanide", "phase": "Solid", "block": "f", "period": 6, "group": "N/A", "electron_config": "[Xe] 4f5 6s2", "electronegativity": 1.13, "melting_point": 1315, "boiling_point": 3273, "density": 7.26, "atomic_radius": 185, "ionization_energy": 540, "electron_affinity": -50, "oxidation_states": "+3", "discovered_by": "Charles D. Coryell", "discovery_year": 1945 }, { "number": 62, "symbol": "Sm", "name": "Samarium", "atomic_mass": 150.36, "category": "Lanthanide", "phase": "Solid", "block": "f", "period": 6, "group": "N/A", "electron_config": "[Xe] 4f6 6s2", "electronegativity": 1.17, "melting_point": 1345, "boiling_point": 2067, "density": 7.52, "atomic_radius": 185, "ionization_energy": 544.5, "electron_affinity": -50, "oxidation_states": "+3", "discovered_by": "Paul Emile Lecoq de Boisbaudran", "discovery_year": 1879 }, { "number": 63, "symbol": "Eu", "name": "Europium", "atomic_mass": 151.96, "category": "Lanthanide", "phase": "Solid", "block": "f", "period": 6, "group": "N/A", "electron_config": "[Xe] 4f7 6s2", "electronegativity": 1.2, "melting_point": 1099, "boiling_point": 1802, "density": 5.243, "atomic_radius": 185, "ionization_energy": 547.1, "electron_affinity": -50, "oxidation_states": "+2, +3", "discovered_by": "Eugene-Anatole Demarcay", "discovery_year": 1901 }, { "number": 64, "symbol": "Gd", "name": "Gadolinium", "atomic_mass": 157.25, "category": "Lanthanide", "phase": "Solid", "block": "f", "period": 6, "group": "N/A", "electron_config": "[Xe] 4f7 5d1 6s2", "electronegativity": 1.2, "melting_point": 1585, "boiling_point": 3546, "density": 7.895, "atomic_radius": 180, "ionization_energy": 593.4, "electron_affinity": -50, "oxidation_states": "+3", "discovered_by": "Jean Charles Galissard de Marignac", "discovery_year": 1880 }, { "number": 65, "symbol": "Tb", "name": "Terbium", "atomic_mass": 158.93, "category": "Lanthanide", "phase": "Solid", "block": "f", "period": 6, "group": "N/A", "electron_config": "[Xe] 4f9 6s2", "electronegativity": 1.2, "melting_point": 1629, "boiling_point": 3503, "density": 8.229, "atomic_radius": 175, "ionization_energy": 565.8, "electron_affinity": -50, "oxidation_states": "+3", "discovered_by": "Carl Gustaf Mosander", "discovery_year": 1843 }, { "number": 66, "symbol": "Dy", "name": "Dysprosium", "atomic_mass": 162.5, "category": "Lanthanide", "phase": "Solid", "block": "f", "period": 6, "group": "N/A", "electron_config": "[Xe] 4f10 6s2", "electronegativity": 1.22, "melting_point": 1680, "boiling_point": 2840, "density": 8.55, "atomic_radius": 175, "ionization_energy": 573, "electron_affinity": -50, "oxidation_states": "+3", "discovered_by": "Paul Emile Lecoq de Boisbaudran", "discovery_year": 1886 }, { "number": 67, "symbol": "Ho", "name": "Holmium", "atomic_mass": 164.93, "category": "Lanthanide", "phase": "Solid", "block": "f", "period": 6, "group": "N/A", "electron_config": "[Xe] 4f11 6s2", "electronegativity": 1.23, "melting_point": 1734, "boiling_point": 2993, "density": 8.795, "atomic_radius": 175, "ionization_energy": 581, "electron_affinity": -50, "oxidation_states": "+3", "discovered_by": "Marc Delafontaine", "discovery_year": 1878 }, { "number": 68, "symbol": "Er", "name": "Erbium", "atomic_mass": 167.26, "category": "Lanthanide", "phase": "Solid", "block": "f", "period": 6, "group": "N/A", "electron_config": "[Xe] 4f12 6s2", "electronegativity": 1.24, "melting_point": 1802, "boiling_point": 3141, "density": 9.066, "atomic_radius": 175, "ionization_energy": 589.3, "electron_affinity": -50, "oxidation_states": "+3", "discovered_by": "Carl Gustaf Mosander", "discovery_year": 1843 }, { "number": 69, "symbol": "Tm", "name": "Thulium", "atomic_mass": 168.93, "category": "Lanthanide", "phase": "Solid", "block": "f", "period": 6, "group": "N/A", "electron_config": "[Xe] 4f13 6s2", "electronegativity": 1.25, "melting_point": 1818, "boiling_point": 2223, "density": 9.321, "atomic_radius": 175, "ionization_energy": 596.7, "electron_affinity": -50, "oxidation_states": "+3", "discovered_by": "Per Teodor Cleve", "discovery_year": 1879 }, { "number": 70, "symbol": "Yb", "name": "Ytterbium", "atomic_mass": 173.05, "category": "Lanthanide", "phase": "Solid", "block": "f", "period": 6, "group": "N/A", "electron_config": "[Xe] 4f14 6s2", "electronegativity": 1.1, "melting_point": 1097, "boiling_point": 1469, "density": 6.965, "atomic_radius": 175, "ionization_energy": 603.4, "electron_affinity": -50, "oxidation_states": "+2, +3", "discovered_by": "Jean Charles Galissard de Marignac", "discovery_year": 1878 }, { "number": 71, "symbol": "Lu", "name": "Lutetium", "atomic_mass": 174.97, "category": "Lanthanide", "phase": "Solid", "block": "d", "period": 6, "group": 3, "electron_config": "[Xe] 4f14 5d1 6s2", "electronegativity": 1.27, "melting_point": 1925, "boiling_point": 3675, "density": 9.84, "atomic_radius": 175, "ionization_energy": 523.5, "electron_affinity": -50, "oxidation_states": "+3", "discovered_by": "Georges Urbain", "discovery_year": 1907 }, { "number": 72, "symbol": "Hf", "name": "Hafnium", "atomic_mass": 178.49, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 6, "group": 4, "electron_config": "[Xe] 4f14 5d2 6s2", "electronegativity": 1.3, "melting_point": 2506, "boiling_point": 4876, "density": 13.31, "atomic_radius": 167, "ionization_energy": 658.5, "electron_affinity": 0, "oxidation_states": "+4", "discovered_by": "Dirk Coster", "discovery_year": 1923 }, { "number": 73, "symbol": "Ta", "name": "Tantalum", "atomic_mass": 180.95, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 6, "group": 5, "electron_config": "[Xe] 4f14 5d3 6s2", "electronegativity": 1.5, "melting_point": 3290, "boiling_point": 5731, "density": 16.654, "atomic_radius": 149, "ionization_energy": 761, "electron_affinity": -31, "oxidation_states": "+5", "discovered_by": "Anders Gustaf Ekeberg", "discovery_year": 1802 }, { "number": 74, "symbol": "W", "name": "Tungsten", "atomic_mass": 183.84, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 6, "group": 6, "electron_config": "[Xe] 4f14 5d4 6s2", "electronegativity": 2.36, "melting_point": 3695, "boiling_point": 5828, "density": 19.25, "atomic_radius": 141, "ionization_energy": 770, "electron_affinity": -79, "oxidation_states": "+4, +6", "discovered_by": "Carl Wilhelm Scheele", "discovery_year": 1783 }, { "number": 75, "symbol": "Re", "name": "Rhenium", "atomic_mass": 186.21, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 6, "group": 7, "electron_config": "[Xe] 4f14 5d5 6s2", "electronegativity": 1.9, "melting_point": 3459, "boiling_point": 5869, "density": 21.02, "atomic_radius": 137, "ionization_energy": 760, "electron_affinity": -15, "oxidation_states": "+4, +7", "discovered_by": "Masataka Ogawa", "discovery_year": 1925 }, { "number": 76, "symbol": "Os", "name": "Osmium", "atomic_mass": 190.23, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 6, "group": 8, "electron_config": "[Xe] 4f14 5d6 6s2", "electronegativity": 2.2, "melting_point": 3306, "boiling_point": 5285, "density": 22.59, "atomic_radius": 135, "ionization_energy": 840, "electron_affinity": -106, "oxidation_states": "+3, +4", "discovered_by": "Smithson Tennant", "discovery_year": 1803 }, { "number": 77, "symbol": "Ir", "name": "Iridium", "atomic_mass": 192.22, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 6, "group": 9, "electron_config": "[Xe] 4f14 5d7 6s2", "electronegativity": 2.2, "melting_point": 2719, "boiling_point": 4701, "density": 22.56, "atomic_radius": 136, "ionization_energy": 880, "electron_affinity": -151, "oxidation_states": "+3, +4", "discovered_by": "Smithson Tennant", "discovery_year": 1803 }, { "number": 78, "symbol": "Pt", "name": "Platinum", "atomic_mass": 195.08, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 6, "group": 10, "electron_config": "[Xe] 4f14 5d9 6s1", "electronegativity": 2.28, "melting_point": 2041.4, "boiling_point": 4098, "density": 21.46, "atomic_radius": 139, "ionization_energy": 870, "electron_affinity": -205, "oxidation_states": "+2, +4", "discovered_by": "Antonio de Ulloa", "discovery_year": 1735 }, { "number": 79, "symbol": "Au", "name": "Gold", "atomic_mass": 196.97, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 6, "group": 11, "electron_config": "[Xe] 4f14 5d10 6s1", "electronegativity": 2.54, "melting_point": 1337.33, "boiling_point": 3129, "density": 19.282, "atomic_radius": 144, "ionization_energy": 890.1, "electron_affinity": -223, "oxidation_states": "+1, +3", "discovered_by": "Ancient", "discovery_year": "Ancient" }, { "number": 80, "symbol": "Hg", "name": "Mercury", "atomic_mass": 200.59, "category": "Transition Metal", "phase": "Liquid", "block": "d", "period": 6, "group": 12, "electron_config": "[Xe] 4f14 5d10 6s2", "electronegativity": 2, "melting_point": 234.32, "boiling_point": 629.88, "density": 13.5336, "atomic_radius": 151, "ionization_energy": 1007.1, "electron_affinity": 0, "oxidation_states": "+1, +2", "discovered_by": "Ancient", "discovery_year": "Ancient" }, { "number": 81, "symbol": "Tl", "name": "Thallium", "atomic_mass": 204.38, "category": "Post-Transition", "phase": "Solid", "block": "p", "period": 6, "group": 13, "electron_config": "[Xe] 4f14 5d10 6s2 6p1", "electronegativity": 1.62, "melting_point": 577, "boiling_point": 1746, "density": 11.85, "atomic_radius": 170, "ionization_energy": 589.4, "electron_affinity": -19, "oxidation_states": "+1, +3", "discovered_by": "William Crookes", "discovery_year": 1861 }, { "number": 82, "symbol": "Pb", "name": "Lead", "atomic_mass": 207.2, "category": "Post-Transition", "phase": "Solid", "block": "p", "period": 6, "group": 14, "electron_config": "[Xe] 4f14 5d10 6s2 6p2", "electronegativity": 1.87, "melting_point": 600.61, "boiling_point": 2022, "density": 11.342, "atomic_radius": 146, "ionization_energy": 715.6, "electron_affinity": -35, "oxidation_states": "+2, +4", "discovered_by": "Ancient", "discovery_year": "Ancient" }, { "number": 83, "symbol": "Bi", "name": "Bismuth", "atomic_mass": 208.98, "category": "Post-Transition", "phase": "Solid", "block": "p", "period": 6, "group": 15, "electron_config": "[Xe] 4f14 5d10 6s2 6p3", "electronegativity": 2.02, "melting_point": 544.7, "boiling_point": 1837, "density": 9.807, "atomic_radius": 148, "ionization_energy": 703, "electron_affinity": -91, "oxidation_states": "+3, +5", "discovered_by": "Claude Francois Geoffroy", "discovery_year": 1753 }, { "number": 84, "symbol": "Po", "name": "Polonium", "atomic_mass": 209, "category": "Post-Transition", "phase": "Solid", "block": "p", "period": 6, "group": 16, "electron_config": "[Xe] 4f14 5d10 6s2 6p4", "electronegativity": 2, "melting_point": 527, "boiling_point": 1235, "density": 9.32, "atomic_radius": 140, "ionization_energy": 812.1, "electron_affinity": -183, "oxidation_states": "+2, +4", "discovered_by": "Marie Curie", "discovery_year": 1898 }, { "number": 85, "symbol": "At", "name": "Astatine", "atomic_mass": 210, "category": "Halogen", "phase": "Solid", "block": "p", "period": 6, "group": 17, "electron_config": "[Xe] 4f14 5d10 6s2 6p5", "electronegativity": 2.2, "melting_point": 575, "boiling_point": 610, "density": 7, "atomic_radius": 150, "ionization_energy": 920, "electron_affinity": -270, "oxidation_states": "-1, +1", "discovered_by": "Dale R. Corson", "discovery_year": 1940 }, { "number": 86, "symbol": "Rn", "name": "Radon", "atomic_mass": 222, "category": "Noble Gas", "phase": "Gas", "block": "p", "period": 6, "group": 18, "electron_config": "[Xe] 4f14 5d10 6s2 6p6", "electronegativity": "N/A", "melting_point": 202, "boiling_point": 211.3, "density": 0.00973, "atomic_radius": 150, "ionization_energy": 1037, "electron_affinity": 0, "oxidation_states": "0", "discovered_by": "Friedrich Ernst Dorn", "discovery_year": 1900 }, { "number": 87, "symbol": "Fr", "name": "Francium", "atomic_mass": 223, "category": "Alkali Metal", "phase": "Solid", "block": "s", "period": 7, "group": 1, "electron_config": "[Rn] 7s1", "electronegativity": 0.7, "melting_point": 300, "boiling_point": 950, "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 380, "electron_affinity": -44, "oxidation_states": "+1", "discovered_by": "Marguerite Perey", "discovery_year": 1939 }, { "number": 88, "symbol": "Ra", "name": "Radium", "atomic_mass": 226, "category": "Alkaline Earth", "phase": "Solid", "block": "s", "period": 7, "group": 2, "electron_config": "[Rn] 7s2", "electronegativity": 0.9, "melting_point": 973, "boiling_point": 2010, "density": 5.5, "atomic_radius": "N/A", "ionization_energy": 509.3, "electron_affinity": 0, "oxidation_states": "+2", "discovered_by": "Marie Curie", "discovery_year": 1898 }, { "number": 89, "symbol": "Ac", "name": "Actinium", "atomic_mass": 227, "category": "Actinide", "phase": "Solid", "block": "f", "period": 7, "group": 3, "electron_config": "[Rn] 6d1 7s2", "electronegativity": 1.1, "melting_point": 1323, "boiling_point": 3471, "density": 10.07, "atomic_radius": "N/A", "ionization_energy": 499, "electron_affinity": 0, "oxidation_states": "+3", "discovered_by": "Friedrich Oskar Giesel", "discovery_year": 1899 }, { "number": 90, "symbol": "Th", "name": "Thorium", "atomic_mass": 232.04, "category": "Actinide", "phase": "Solid", "block": "f", "period": 7, "group": "N/A", "electron_config": "[Rn] 6d2 7s2", "electronegativity": 1.3, "melting_point": 2115, "boiling_point": 5061, "density": 11.72, "atomic_radius": 179, "ionization_energy": 587, "electron_affinity": 0, "oxidation_states": "+4", "discovered_by": "Jons Jacob Berzelius", "discovery_year": 1829 }, { "number": 91, "symbol": "Pa", "name": "Protactinium", "atomic_mass": 231.04, "category": "Actinide", "phase": "Solid", "block": "f", "period": 7, "group": "N/A", "electron_config": "[Rn] 5f2 6d1 7s2", "electronegativity": 1.5, "melting_point": 1841, "boiling_point": 4300, "density": 15.37, "atomic_radius": 163, "ionization_energy": 568, "electron_affinity": 0, "oxidation_states": "+5", "discovered_by": "Kasimir Fajans", "discovery_year": 1913 }, { "number": 92, "symbol": "U", "name": "Uranium", "atomic_mass": 238.03, "category": "Actinide", "phase": "Solid", "block": "f", "period": 7, "group": "N/A", "electron_config": "[Rn] 5f3 6d1 7s2", "electronegativity": 1.38, "melting_point": 1405.3, "boiling_point": 4404, "density": 18.95, "atomic_radius": 156, "ionization_energy": 597.6, "electron_affinity": 0, "oxidation_states": "+4, +6", "discovered_by": "Martin Heinrich Klaproth", "discovery_year": 1789 }, { "number": 93, "symbol": "Np", "name": "Neptunium", "atomic_mass": 237, "category": "Actinide", "phase": "Solid", "block": "f", "period": 7, "group": "N/A", "electron_config": "[Rn] 5f4 6d1 7s2", "electronegativity": 1.36, "melting_point": 917, "boiling_point": 4273, "density": 20.45, "atomic_radius": 155, "ionization_energy": 604.5, "electron_affinity": 0, "oxidation_states": "+5", "discovered_by": "Edwin McMillan", "discovery_year": 1940 }, { "number": 94, "symbol": "Pu", "name": "Plutonium", "atomic_mass": 244, "category": "Actinide", "phase": "Solid", "block": "f", "period": 7, "group": "N/A", "electron_config": "[Rn] 5f6 7s2", "electronegativity": 1.28, "melting_point": 912.5, "boiling_point": 3501, "density": 19.84, "atomic_radius": 159, "ionization_energy": 584.7, "electron_affinity": 0, "oxidation_states": "+4", "discovered_by": "Glenn T. Seaborg", "discovery_year": 1940 }, { "number": 95, "symbol": "Am", "name": "Americium", "atomic_mass": 243, "category": "Actinide", "phase": "Solid", "block": "f", "period": 7, "group": "N/A", "electron_config": "[Rn] 5f7 7s2", "electronegativity": 1.3, "melting_point": 1449, "boiling_point": 2880, "density": 13.69, "atomic_radius": 173, "ionization_energy": 578, "electron_affinity": 0, "oxidation_states": "+3", "discovered_by": "Glenn T. Seaborg", "discovery_year": 1944 }, { "number": 96, "symbol": "Cm", "name": "Curium", "atomic_mass": 247, "category": "Actinide", "phase": "Solid", "block": "f", "period": 7, "group": "N/A", "electron_config": "[Rn] 5f7 6d1 7s2", "electronegativity": 1.3, "melting_point": 1613, "boiling_point": 3383, "density": 13.51, "atomic_radius": 174, "ionization_energy": 581, "electron_affinity": 0, "oxidation_states": "+3", "discovered_by": "Glenn T. Seaborg", "discovery_year": 1944 }, { "number": 97, "symbol": "Bk", "name": "Berkelium", "atomic_mass": 247, "category": "Actinide", "phase": "Solid", "block": "f", "period": 7, "group": "N/A", "electron_config": "[Rn] 5f9 7s2", "electronegativity": 1.3, "melting_point": 1259, "boiling_point": 2900, "density": 14.79, "atomic_radius": "N/A", "ionization_energy": 601, "electron_affinity": 0, "oxidation_states": "+3", "discovered_by": "Glenn T. Seaborg", "discovery_year": 1949 }, { "number": 98, "symbol": "Cf", "name": "Californium", "atomic_mass": 251, "category": "Actinide", "phase": "Solid", "block": "f", "period": 7, "group": "N/A", "electron_config": "[Rn] 5f10 7s2", "electronegativity": 1.3, "melting_point": 1173, "boiling_point": 1743, "density": 15.1, "atomic_radius": "N/A", "ionization_energy": 608, "electron_affinity": 0, "oxidation_states": "+3", "discovered_by": "Glenn T. Seaborg", "discovery_year": 1950 }, { "number": 99, "symbol": "Es", "name": "Einsteinium", "atomic_mass": 252, "category": "Actinide", "phase": "Solid", "block": "f", "period": 7, "group": "N/A", "electron_config": "[Rn] 5f11 7s2", "electronegativity": 1.3, "melting_point": 1133, "boiling_point": 1269, "density": 8.84, "atomic_radius": "N/A", "ionization_energy": 619, "electron_affinity": 0, "oxidation_states": "+3", "discovered_by": "Albert Ghiorso", "discovery_year": 1952 }, { "number": 100, "symbol": "Fm", "name": "Fermium", "atomic_mass": 257, "category": "Actinide", "phase": "Solid", "block": "f", "period": 7, "group": "N/A", "electron_config": "[Rn] 5f12 7s2", "electronegativity": 1.3, "melting_point": 1800, "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 627, "electron_affinity": 0, "oxidation_states": "+3", "discovered_by": "Albert Ghiorso", "discovery_year": 1952 }, { "number": 101, "symbol": "Md", "name": "Mendelevium", "atomic_mass": 258, "category": "Actinide", "phase": "Solid", "block": "f", "period": 7, "group": "N/A", "electron_config": "[Rn] 5f13 7s2", "electronegativity": 1.3, "melting_point": 1100, "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 635, "electron_affinity": 0, "oxidation_states": "+3", "discovered_by": "Albert Ghiorso", "discovery_year": 1955 }, { "number": 102, "symbol": "No", "name": "Nobelium", "atomic_mass": 259, "category": "Actinide", "phase": "Solid", "block": "f", "period": 7, "group": "N/A", "electron_config": "[Rn] 5f14 7s2", "electronegativity": 1.3, "melting_point": 1100, "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 642, "electron_affinity": 0, "oxidation_states": "+2, +3", "discovered_by": "Joint Institute for Nuclear Research", "discovery_year": 1966 }, { "number": 103, "symbol": "Lr", "name": "Lawrencium", "atomic_mass": 266, "category": "Actinide", "phase": "Solid", "block": "d", "period": 7, "group": 3, "electron_config": "[Rn] 5f14 7s2 7p1", "electronegativity": 1.3, "melting_point": 1900, "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 470, "electron_affinity": 0, "oxidation_states": "+3", "discovered_by": "Albert Ghiorso", "discovery_year": 1961 }, { "number": 104, "symbol": "Rf", "name": "Rutherfordium", "atomic_mass": 267, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 7, "group": 4, "electron_config": "[Rn] 5f14 6d2 7s2", "electronegativity": "N/A", "melting_point": "N/A", "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 580, "electron_affinity": 0, "oxidation_states": "+4", "discovered_by": "Joint Institute for Nuclear Research", "discovery_year": 1964 }, { "number": 105, "symbol": "Db", "name": "Dubnium", "atomic_mass": 268, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 7, "group": 5, "electron_config": "[Rn] 5f14 6d3 7s2", "electronegativity": "N/A", "melting_point": "N/A", "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 665, "electron_affinity": 0, "oxidation_states": "+5", "discovered_by": "Albert Ghiorso", "discovery_year": 1967 }, { "number": 106, "symbol": "Sg", "name": "Seaborgium", "atomic_mass": 269, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 7, "group": 6, "electron_config": "[Rn] 5f14 6d4 7s2", "electronegativity": "N/A", "melting_point": "N/A", "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 757, "electron_affinity": 0, "oxidation_states": "+6", "discovered_by": "Albert Ghiorso", "discovery_year": 1974 }, { "number": 107, "symbol": "Bh", "name": "Bohrium", "atomic_mass": 270, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 7, "group": 7, "electron_config": "[Rn] 5f14 6d5 7s2", "electronegativity": "N/A", "melting_point": "N/A", "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 740, "electron_affinity": 0, "oxidation_states": "+7", "discovered_by": "Peter Armbruster", "discovery_year": 1981 }, { "number": 108, "symbol": "Hs", "name": "Hassium", "atomic_mass": 277, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 7, "group": 8, "electron_config": "[Rn] 5f14 6d6 7s2", "electronegativity": "N/A", "melting_point": "N/A", "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 730, "electron_affinity": 0, "oxidation_states": "+8", "discovered_by": "Peter Armbruster", "discovery_year": 1984 }, { "number": 109, "symbol": "Mt", "name": "Meitnerium", "atomic_mass": 278, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 7, "group": 9, "electron_config": "[Rn] 5f14 6d7 7s2", "electronegativity": "N/A", "melting_point": "N/A", "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 800, "electron_affinity": 0, "oxidation_states": "+3", "discovered_by": "Peter Armbruster", "discovery_year": 1982 }, { "number": 110, "symbol": "Ds", "name": "Darmstadtium", "atomic_mass": 281, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 7, "group": 10, "electron_config": "[Rn] 5f14 6d8 7s2", "electronegativity": "N/A", "melting_point": "N/A", "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 900, "electron_affinity": 0, "oxidation_states": "N/A", "discovered_by": "Peter Armbruster", "discovery_year": 1994 }, { "number": 111, "symbol": "Rg", "name": "Roentgenium", "atomic_mass": 282, "category": "Transition Metal", "phase": "Solid", "block": "d", "period": 7, "group": 11, "electron_config": "[Rn] 5f14 6d9 7s2", "electronegativity": "N/A", "melting_point": "N/A", "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 1020, "electron_affinity": 0, "oxidation_states": "N/A", "discovered_by": "Peter Armbruster", "discovery_year": 1994 }, { "number": 112, "symbol": "Cn", "name": "Copernicium", "atomic_mass": 285, "category": "Transition Metal", "phase": "Liquid", "block": "d", "period": 7, "group": 12, "electron_config": "[Rn] 5f14 6d10 7s2", "electronegativity": "N/A", "melting_point": "N/A", "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 1155, "electron_affinity": 0, "oxidation_states": "+2", "discovered_by": "Sigurd Hofmann", "discovery_year": 1996 }, { "number": 113, "symbol": "Nh", "name": "Nihonium", "atomic_mass": 286, "category": "Post-Transition", "phase": "Solid", "block": "p", "period": 7, "group": 13, "electron_config": "[Rn] 5f14 6d10 7s2 7p1", "electronegativity": "N/A", "melting_point": "N/A", "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 707, "electron_affinity": 0, "oxidation_states": "N/A", "discovered_by": "RIKEN", "discovery_year": 2003 }, { "number": 114, "symbol": "Fl", "name": "Flerovium", "atomic_mass": 289, "category": "Post-Transition", "phase": "Solid", "block": "p", "period": 7, "group": 14, "electron_config": "[Rn] 5f14 6d10 7s2 7p2", "electronegativity": "N/A", "melting_point": "N/A", "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 832, "electron_affinity": 0, "oxidation_states": "N/A", "discovered_by": "Joint Institute for Nuclear Research", "discovery_year": 1998 }, { "number": 115, "symbol": "Mc", "name": "Moscovium", "atomic_mass": 290, "category": "Post-Transition", "phase": "Solid", "block": "p", "period": 7, "group": 15, "electron_config": "[Rn] 5f14 6d10 7s2 7p3", "electronegativity": "N/A", "melting_point": "N/A", "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 538, "electron_affinity": 0, "oxidation_states": "N/A", "discovered_by": "Joint Institute for Nuclear Research", "discovery_year": 2003 }, { "number": 116, "symbol": "Lv", "name": "Livermorium", "atomic_mass": 293, "category": "Post-Transition", "phase": "Solid", "block": "p", "period": 7, "group": 16, "electron_config": "[Rn] 5f14 6d10 7s2 7p4", "electronegativity": "N/A", "melting_point": "N/A", "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 663, "electron_affinity": 0, "oxidation_states": "N/A", "discovered_by": "Joint Institute for Nuclear Research", "discovery_year": 2000 }, { "number": 117, "symbol": "Ts", "name": "Tennessine", "atomic_mass": 294, "category": "Halogen", "phase": "Solid", "block": "p", "period": 7, "group": 17, "electron_config": "[Rn] 5f14 6d10 7s2 7p5", "electronegativity": "N/A", "melting_point": "N/A", "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 736, "electron_affinity": 0, "oxidation_states": "N/A", "discovered_by": "Joint Institute for Nuclear Research", "discovery_year": 2010 }, { "number": 118, "symbol": "Og", "name": "Oganesson", "atomic_mass": 294, "category": "Noble Gas", "phase": "Solid", "block": "p", "period": 7, "group": 18, "electron_config": "[Rn] 5f14 6d10 7s2 7p6", "electronegativity": "N/A", "melting_point": "N/A", "boiling_point": "N/A", "density": "N/A", "atomic_radius": "N/A", "ionization_energy": 839, "electron_affinity": 0, "oxidation_states": "N/A", "discovered_by": "Joint Institute for Nuclear Research", "discovery_year": 2002 } ]