Periodic Table

Hydrogen and the alkali metals

elements with a s¹ configuration outside a non-oxidizable core

Hydrogen

Atomic configuration: 1s¹

Atomic mass: 1.0079

Pauling electronegativity: 2.1

Common oxidation states: ±1

Ionization energy: 1312 kJ mol^-1

Electron affinity: 72 kJ mol^-1

Melting point: 14 K

Boiling point: 20 K

identified in 1766 by H. Cavendish from action of acid on metal

Lithium

Atomic configuration: [He] 2s¹

Atomic mass: 6.941

Pauling electronegativity: 0.98

Common oxidation states: +1

Ionization energy: 520 kJ mol^-1

Electron affinity: 60 kJ mol^-1

Melting point: 454 K

Boiling point: 1615 K

identified in 1817 by Arfvedson and isolated from mineral petalite

Sodium

Atomic configuration: [Ne] 3s¹

Atomic mass: 22.9898

Pauling electronegativity: 0.93

Common oxidation states: +1

Ionization energy: 496 kJ mol^-1

Electron affinity: 53 kJ mol^-1

Melting point: 371 K

Boiling point: 1156 K

isolated by Davy in 1807 by electrolysis of NaOH days after discovery of K

Potassium

Atomic configuration: [Ar] 4s¹

Atomic mass: 39.0983

Pauling electronegativity: 0.82

Common oxidation states: +1

Ionization energy: 419 kJ mol^-1

Electron affinity: 49 kJ mol^-1

Melting point: 337 K

Boiling point: 1033 K

isolated by Davy in 1807 by electrolysis of molten KOH when 29 years old

Rubidium

Atomic configuration: [Kr] 5s¹

Atomic mass: 85.4678

Pauling electronegativity: 0.82

Common oxidation states: +1

Ionization energy: 403 kJ mol^-1

Electron affinity: 47 kJ mol^-1

Melting point: 313 K

Boiling point: 961 K

identified in 1861 by Bunsen and Kirchoff in mineral lepidolite

Caesium

Atomic configuration: [Xe] 6s¹

Atomic mass: 132.9054

Pauling electronegativity: 0.79

Common oxidation states: +1

Ionization energy: 376 kJ mol^-1

Electron affinity: 46 kJ mol^-1

Melting point: 302 K

Boiling point: 944 K

identified in 1860 by Bunsen and Kirchoff in mineral spa waters

Francium

Atomic configuration: [Rn] 7s¹

Atomic mass: (223)

Pauling electronegativity: 0.71

Common oxidation states: +1

Ionization energy: ~375 kJ mol^-1

Electron affinity: ~44 kJ mol^-1

Melting point: 300 K

Boiling point: 950 K

identified in 1939 by Percy from radioactive decay of Ac

The alkaline earths

elements with a s² configuration outside a noble gas core

Beryllium

Atomic configuration: [He] 2s²

Atomic mass: 9.0122

Pauling electronegativity: 1.57

Common oxidation states: +2

Ionization energy: 899 kJ mol^-1

Electron affinity: 0 kJ mol^-1

Melting point: 1289 K

Boiling point: 2472 K

identified in 1798 by Vauquelin in beryllia from beryl and emerald

Magnesium

Atomic configuration: [Ne] 3s²

Atomic mass: 24.305

Pauling electronegativity: 1.31

Common oxidation states: +2

Ionization energy: 738 kJ mol^-1

Electron affinity: 0 kJ mol^-1

Melting point: 650 K

Boiling point: 1090 K

known since antiquity: isolated by Davy (1808) by electrolysis

Calcium

Atomic configuration: [Ar] 4s²

Atomic mass: 40.08

Pauling electronegativity: 1.00

Common oxidation states: +2

Ionization energy: 590 kJ mol^-1

Electron affinity: 0 kJ mol^-1

Melting point: 842 K

Boiling point: 1494 K

known since antiquity: isolated by Davy (1808) by electrolysis

Strontium

Atomic configuration: [Kr] 5s²

Atomic mass: 87.62

Pauling electronegativity: 0.95

Common oxidation states: +2

Ionization energy: 550 kJ mol^-1

Electron affinity: 0 kJ mol^-1

Melting point: 769 K

Boiling point: 1382 K

identified by Crawford in 1790 and confirmed by Hope in 1791

Barium

Atomic configuration: [Xe] 6s²

Atomic mass: 137.33

Pauling electronegativity: 0.89

Common oxidation states: +2

Ionization energy: 503 kJ mol^-1

Electron affinity: 0 kJ mol^-1

Melting point: 729 K

Boiling point: 1805 K

known since the 17th Century and isolated by Davy in 1808

Radium

Atomic configuration: [Rn] 7s²

Atomic mass: 226.03

Pauling electronegativity: 0.90

Common oxidation states: +2

Ionization energy: 509 kJ mol^-1

Electron affinity: -

Melting point: 700 K

Boiling point: (1700 K)

isolated by the Curies in 1898 by processing tonnes of pitchblende

Group 3

elements with a s²d¹ configuration outside a noble gas core

Scandium

Atomic configuration: [Ar] 4s²3d¹

Atomic mass: 44.956

Pauling electronegativity: 1.3

Common oxidation states: +3

Ionization energy: 633 kJ mol^-1

Electron affinity: 18 kJ mol^-1

Melting point: 1539 K

Boiling point: 2748 K

identified in 1879 by Nilsen and isolated in 1937 by electrolysis

Yttrium

Atomic configuration: [Kr] 5s²4d¹

Atomic mass: 88.906

Pauling electronegativity: 1.2

Common oxidation states: +3

Ionization energy: 600 kJ mol^-1

Electron affinity: 30 kJ mol^-1

Melting point: 1530 K

Boiling point: 3264 K

oxide separated in 1843 by Mosander from mineral yttria

Lanthanum

Atomic configuration: [Xe] 6s²5d¹

Atomic mass: 138.906

Pauling electronegativity: 1.1

Common oxidation states: +3

Ionization energy: 538 kJ mol^-1

Electron affinity: 48 kJ mol^-1

Melting point: 920 K

Boiling point: 3420 K

oxide extracted in 1839 by Mosander from cerium nitrate

Actinium

Atomic configuration: [Rn] 7s²6d²

Atomic mass: 227.028

Pauling electronegativity: 1.1

Common oxidation states: +3

Ionization energy: 499 kJ mol^-1

Electron affinity: -

Melting point: 817 K

Boiling point: 2470 K

identified in 1899 by Debierne in urannium minerals

Group 4

elements with a s²d² configuration outside a noble gas core

Titanium

Atomic configuration: [Ar] 4s²3d²

Atomic mass: 47.88

Pauling electronegativity: 1.5

Common oxidation states: +2, +3, +4

Ionization energy: 659 kJ mol^-1

Electron affinity: 8 kJ mol^-1

Melting point: 1667 K

Boiling point: 3285 K

identified in 1791 by Cornish vicar Gregor in sand from the river Helford

Zirconium

Atomic configuration: [Kr] 5s²4d²

Atomic mass: 91.22

Pauling electronegativity: 1.4

Common oxidation states: +3, +4

Ionization energy: 640 kJ mol^-1

Electron affinity: 41 kJ mol^-1

Melting point: 1857 K

Boiling point: 4200 K

discovered in 1789 by German chemist Klaproth in rutile ore

Hafnium

Atomic configuration: [Xe] 4f¹⁴6s²5d²

Atomic mass: 178.49

Pauling electronegativity: 1.3

Common oxidation states: +3, +4

Ionization energy: 659 kJ mol^-1

Electron affinity: 0 kJ mol^-1

Melting point: 2222 K

Boiling point: 4450 K

identified in 1922 by Coster and von Gersey using X-ray spectroscopy on zircon

Rutherfordium

Atomic configuration: [Rn] 5f¹⁴7s²6d¹

Atomic mass: (263)

Pauling electronegativity: -

Common oxidation states: -

Ionization energy: -

Electron affinity: -

Melting point: -

Boiling point: -

synthesized in 1964 in Dubna and in 1969 in Berkeley by high energy collisions

Group 5

elements with a s²d³ configuration outside a noble gas core

Vanadium

Atomic configuration: [Ar] 4s²3d³

Atomic mass: 50.94'

Pauling electronegativity: 1.6

Common oxidation states: +2, +3, +4, +5

Ionization energy: 651 kJ mol^-1

Electron affinity: 51 kJ mol^-1

Melting point: 1915 K

Boiling point: 3350 K

discovered twice in 1801 by del Rio and in 1830 by Sefstr�m

Niobium

Atomic configuration: [Kr] 5s²4d³

Atomic mass: 92.91

Pauling electronegativity: 1.6

Common oxidation states: +2, +3, +4, +5

Ionization energy: 652 kJ mol^-1

Electron affinity: 86 kJ mol^-1

Melting point: 2468 K

Boiling point: 4758 K

discovered by Hatchett in 1801 and originally called columbian

Tantalum

Atomic configuration: [Xe] 4f¹⁴6s²5d³

Atomic mass: 180.95

Pauling electronegativity: 1.5

Common oxidation states: +2, +3, +4, +5

Ionization energy: 761 kJ mol^-1

Electron affinity: 31 kJ mol^-1

Melting point: 2980 K

Boiling point: 534 K

identified in Sweden by Ekeberg in 1802 in Finnish minerals

Dubnium

Atomic configuration: [Rn] 5f¹⁴7s²6d³

Atomic mass: (262)

Pauling electronegativity: -

Common oxidation states: -

Ionization energy: -

Electron affinity: -

Melting point: -

Boiling point: -

made in Dubna in 1967 and in Berkeley in 1970 by atom bombardment

Group 6

elements with 6 valence electrons and sⁿd^m configurations

Chromium

Atomic configuration: [Ar] 4s¹3d⁵

Atomic mass: 52.00'

Pauling electronegativity: 1.8

Common oxidation states: +2, +3, +4, +5, +6

Ionization energy: 653 kJ mol^-1

Electron affinity: 54 kJ mol^-1

Melting point: 1244 K

Boiling point: 2060 K

discovered in 1797 by Vauquelin in the mineral crocoite

Molybdenum

Atomic configuration: [Kr] 5s¹4d⁵

Atomic mass: 95.94

Pauling electronegativity: 2.26

Common oxidation states: +2, +3, +4, +5

Ionization energy: 684 kJ mol^-1

Electron affinity: 72 kJ mol^-1

Melting point: 2200 K

Boiling point: 4567 K

identified in 1778 by Scheele in the mineral now called molybdenite

Tungsten

Atomic configuration: [Xe] 4f¹⁴6s²5d⁴

Atomic mass: 183.84

Pauling electronegativity: 2.2

Common oxidation states: +2, +3, +4, +5, +6

Ionization energy: 770 kJ mol^-1

Electron affinity: 79 kJ mol^-1

Melting point: 3695 K

Boiling point: 5828 K

identified in 1781 by Scheele and Bergman in the mineral scheelite

Seaborgium

Atomic configuration: [Rn] -

Atomic mass: (266)

Pauling electronegativity: -

Common oxidation states: -

Ionization energy: -

Electron affinity: -

Melting point: -

Boiling point: -

made in 1974 in the Soviet Joint Institute for Nuclear Research from Cr and Pb

Group 7

elements with 7 valence electrons and sⁿd^m configurations

Manganese

Atomic configuration: [Ar] 4s²3d⁵

Atomic mass: 54.94'

Pauling electronegativity: 1.5

Common oxidation states: +2, +3, +4, +5, +6, +7

Ionization energy: 717 kJ mol^-1

Electron affinity: 0 kJ mol^-1

Melting point: 1900 K

Boiling point: 2690 K

isolated in 1774 by Scheele and Gahn from the mineral pyrolusite

Technetium

Atomic configuration: [Kr] 5s¹4d⁶

Atomic mass: (98)

Pauling electronegativity: 1.9

Common oxidation states: +2, +3, +4, +5, +6, +7

Ionization energy: 702 kJ mol^-1

Electron affinity: 53 kJ mol^-1

Melting point: 1900 K

Boiling point: 2690 K

first artificial element, made by Perrier and Segr� in 1937 by firing neutrons at Mo

Rhenium

Atomic configuration: [Xe] 4f¹⁴6s²5d⁵

Atomic mass: 186.21

Pauling electronegativity: 1.95

Common oxidation states: +2, +3, +4, +5, +6, +7

Ionization energy: 760 kJ mol^-1

Electron affinity: 15 kJ mol^-1

Melting point: 3180 K

Boiling point: 5869 K

discovered in 1925 by Noddack, Tacke and Berg in mineral gadolinite

Bohrium

Atomic configuration: [Rn] -

Atomic mass: (264)

Pauling electronegativity: -

Common oxidation states: -

Ionization energy: -

Electron affinity: -

Melting point: -

Boiling point: -

made in USSR in 1974 and in Darmstadt in 1981 by atom bombardment

Group 8

elements with 8 valence electrons and sⁿd^m configurations

Iron

Atomic configuration: [Ar] 4s²3d⁶

Atomic mass: 55.85'

Pauling electronegativity: 1.8

Common oxidation states: +2, +3, +4, +5, +6

Ionization energy: 763 kJ mol^-1

Electron affinity: 16 kJ mol^-1

Melting point: 1495 K

Boiling point: 3100 K

known since prehistory and first smelted around 3000BC in Asia Minor

Ruthenium

Atomic configuration: [Kr] 5s¹4d⁷

Atomic mass: 101.07

Pauling electronegativity: 2.2

Common oxidation states: +2, +3, +4, +5, +6, +7, +8

Ionization energy: 710 kJ mol^-1

Electron affinity: 101 kJ mol^-1

Melting point: 1495 K

Boiling point: 3100 K

discovered in 1844 by Klaus in residue after Pt is dissolved in aqua regia

Osmium

Atomic configuration: [Xe] 4f¹⁴6s²5d⁶

Atomic mass: 190.2

Pauling electronegativity: 2.2

Common oxidation states: +2, +3, +4, +5, +6, +7, +8

Ionization energy: 840 kJ mol^-1

Electron affinity: 106 kJ mol^-1

Melting point: 1495 K

Boiling point: 3100 K

discovered in 1803 by Tenant in residue after Pt is dissolved in aqua regia

Hassium

Atomic configuration: [Rn] -

Atomic mass: (269)

Pauling electronegativity: -

Common oxidation states: -

Ionization energy: -

Electron affinity: -

Melting point: -

Boiling point: -

made in 1984 in Darmstadt, Germany, by fast atom bombardment

Group 9

elements with a 9 valence electrons and sⁿd^m configurations

Cobalt

Atomic configuration: [Ar] 4s²3d⁷

Atomic mass: 58.93'

Pauling electronegativity: 1.8

Common oxidation states: +2, +3, +4

Ionization energy: 760 kJ mol^-1

Electron affinity: 64 kJ mol^-1

Melting point: 1495 K

Boiling point: 3100 K

ores used for colour since antiquity and isolated in 1735 by Brandt

Rhodium

Atomic configuration: [Kr] 5s¹4d⁸

Atomic mass: 102.91

Pauling electronegativity: 1.8

Common oxidation states: +1, +2, +3, +4, +5, +6

Ionization energy: 720 kJ mol^-1

Electron affinity: 110 kJ mol^-1

Melting point: 1960 K

Boiling point: 3760 K

discovered in 1803 by Wollaston in residue after Pt is dissolved in aqua regia

Iridium

Atomic configuration: [Xe] 4f¹⁴6s²5d⁷

Atomic mass: 192.22

Pauling electronegativity: 1.8

Common oxidation states: +1, +3, +4, +5, +6

Ionization energy: 880 kJ mol^-1

Electron affinity: 151 kJ mol^-1

Melting point: 2443 K

Boiling point: 4550 K

discovered in 1803 by Tenant in residue after Pt is dissolved in aqua regia

Meitnerium

Atomic configuration: [Rn] -

Atomic mass: (268)

Pauling electronegativity: -

Common oxidation states: -

Ionization energy: -

Electron affinity: -

Melting point: -

Boiling point: -

one atom made in 1982 in Darmstadt by fusing an Fe and a Bi atom

Group 10

elements with 10 valence electrons and sⁿd^m configurations

Nickel

Atomic configuration: [Ar] 3d⁸4s²

Atomic mass: 58.69

Pauling electronegativity: 1.8

Common oxidation states: +2, +3, +4

Ionization energy: 737 kJ mol^-1

Electron affinity: 112 kJ mol^-1

Melting point: 1455 K

Boiling point: 2920 K

used in China over 2000 years ago and isolated in 1751 by Cronstedt

Palladium

Atomic configuration: [Kr] 4d¹⁰

Atomic mass: 106.42

Pauling electronegativity: 2.2

Common oxidation states: +2, +3, +4

Ionization energy: 804 kJ mol^-1

Electron affinity: 54 kJ mol^-1

Melting point: 1552 K

Boiling point: 2940 K

isolated in 1803 by Wollaston when studying chemistry of platinum

Platinum

Atomic configuration: [Xe] 4f¹⁴5d⁹6s¹

Atomic mass: 195.08

Pauling electronegativity: 2.2

Common oxidation states: +2, +3, +4, +5, +6

Ionization energy: 870 kJ mol^-1

Electron affinity: 205 kJ mol^-1

Melting point: 1769 K

Boiling point: 4170 K

used for jewellery in ancient Egypt and by the Indians of Ecuador

Ununnilium

Atomic configuration: [Rn] -

Atomic mass: (272)

Pauling electronegativity: -

Common oxidation states: -

Ionization energy: -

Electron affinity: -

Melting point: -

Boiling point: -

one atom made in Darmstadt in 1994 by fusing a Ni and a Pb atom together

The coinage metals

elements with a d¹⁰s¹d configuration outside a noble gas core

Copper

Atomic configuration: [Ar] 3d¹⁰4s¹

Atomic mass: 63.55

Pauling electronegativity: 1.9

Common oxidation states: +1, +2, +3

Ionization energy: 745 kJ mol^-1

Electron affinity: 118 kJ mol^-1

Melting point: 1083 K

Boiling point: 2570 K

known since 5000BC, mixed with tin in India in ~3000BC to start Bronze Age

Silver

Atomic configuration: [Kr] 4d¹⁰5s¹

Atomic mass: 107.87

Pauling electronegativity: 1.9

Common oxidation states: +1, +2, +3

Ionization energy: 731 kJ mol^-1

Electron affinity: 126 kJ mol^-1

Melting point: 961 K

Boiling point: 2155 K

used as currency since 3000BC in many of the classical civilizations

Gold

Atomic configuration: [Xe] 4f¹⁴5d¹⁰6s¹

Atomic mass: 196.97

Pauling electronegativity: 2.4

Common oxidation states: +1, +2, +3, +4, +5

Ionization energy: 890 kJ mol^-1

Electron affinity: 223 kJ mol^-1

Melting point: 1064 K

Boiling point: 2808 K

used as currency by ancient societies including Egypt around 3400BC

Unununium

Atomic configuration: [Rn] 5f¹⁴6d¹⁰7s¹

Atomic mass: (277)

Pauling electronegativity: -

Common oxidation states: -

Ionization energy: -

Electron affinity: -

Melting point: -

Boiling point: -

made in 1994 in Darmstadt by hitting Bi atoms with high energy Ni atoms

Group 12

elements with a d¹⁰s²d configuration outside a noble gas core

Zinc

Atomic configuration: [Ar] 3d¹⁰4s²

Atomic mass: 65.38

Pauling electronegativity: 1.65

Common oxidation states: +2

Ionization energy: 906 kJ mol^-1

Electron affinity: 0 kJ mol^-1

Melting point: 693 K

Boiling point: 1180 K

separation from oxide probably first achieved in India in 13th Century

Cadmium

Atomic configuration: [Kr] 4d¹⁰5s²

Atomic mass: 112.41

Pauling electronegativity: 1.69

Common oxidation states: +2

Ionization energy: 868 kJ mol^-1

Electron affinity: 0 kJ mol^-1

Melting point: 594 K

Boiling point: 1040 K

observed in 1817 by Stromeyer as yellow impurity in calamine

Mercury

Atomic configuration: [Xe] 4f¹⁴5d¹⁰6s²

Atomic mass: 200.59

Pauling electronegativity: 2.0

Common oxidation states: +1, +2

Ionization energy: 1007 kJ mol^-1

Electron affinity: 0 kJ mol^-1

Melting point: 234 K

Boiling point: 630 K

used to extract metals by amalgamation since before 500 BC

Ununbium

Atomic configuration: [Rn] 5f¹⁴6d¹⁰7s²

Atomic mass: (277)

Pauling electronegativity: -

Common oxidation states: -

Ionization energy: -

Electron affinity: -

Melting point: -

Boiling point: -

made in 1996 in Darmstadt by fusing zinc and lead atoms

Boron

Atomic configuration: [He] 2s²2p¹

Atomic mass: 10.81

Pauling electronegativity: 2.04

Common oxidation states: ±3

Ionization energy: 801 kJ mol^-1

Electron affinity: 27 kJ mol^-1

Melting point: 2092 K

Boiling point: 4002 K

known since antiquity and isolated in 1808 by Davy, Gay, Lussac & Th�nard

Aluminium

Atomic configuration: [Ne] 3s²3p¹

Atomic mass: 26.982

Pauling electronegativity: 1.61

Common oxidation states: +3

Ionization energy: 578 kJ mol^-1

Electron affinity: 43 kJ mol^-1

Melting point: 660 K

Boiling point: 2520 K

known since antiquity and isolated in 1825 by Oersted. (Called aluminum in the US)

Gallium

Atomic configuration: [Ar] 3d¹⁰4s²4p¹

Atomic mass: 69.72

Pauling electronegativity: 1.00

Common oxidation states: +1, +3

Ionization energy: 579 kJ mol^-1

Electron affinity: 29 kJ mol^-1

Melting point: 303 K

Boiling point: 2205 K

discoved by de Boisaudran in 1875 using spectroscope and isolated from zinc blende

Indium

Atomic configuration: [Kr] 4d¹⁰5s²5p¹

Atomic mass: 114.82

Pauling electronegativity: 1.78

Common oxidation states: +1, +3

Ionization energy: 558 kJ mol^-1

Electron affinity: 29 kJ mol^-1

Melting point: 157 K

Boiling point: 2073 K

identified in 1863 by Reich and Richter using spectroscope

Thallium

Atomic configuration: [Xe] 4f¹⁴5d¹⁰6s²6p¹

Atomic mass: 204.383

Pauling electronegativity: 1.62

Common oxidation states: +1, +3

Ionization energy: 580 kJ mol^-1

Electron affinity: 19 kJ mol^-1

Melting point: 304 K

Boiling point: 1473 K

identified in 1861/2 independently by Crookes and Lamy

Carbon

Atomic configuration: [He] 2s²2p²

Atomic mass: 12.011

Pauling electronegativity: 2.5

Common oxidation states: ±4

Ionization energy: 1086 kJ mol^-1

Electron affinity: 154 kJ mol^-1

Melting point: 3800 K

Boiling point: 4300 K

known in prehistory and identified as an element in the 18th Century

Silicon

Atomic configuration: [Ne] 3s²3p²

Atomic mass: 26.982

Pauling electronegativity: 1.8

Common oxidation states: +4

Ionization energy: 786 kJ mol^-1

Electron affinity: 134 kJ mol^-1

Melting point: 1420 K

Boiling point: 3280 K

known in prehistory and isolated in 1823 by J J Berzelius

Germanium

Atomic configuration: [Ar] 3d¹⁰4s²4p²

Atomic mass: 72.59

Pauling electronegativity: 1.8

Common oxidation states: +2, +4

Ionization energy: 761 kJ mol^-1

Electron affinity: 119 kJ mol^-1

Melting point: 945 K

Boiling point: 2850 K

predicted by Newlands and Mendeleev and idenified in 1886 by Winkler

Tin

Atomic configuration: [Kr] 4d¹⁰5s²5p²

Atomic mass: 118.69

Pauling electronegativity: 1.8

Common oxidation states: +2, +4

Ionization energy: 708 kJ mol^-1

Electron affinity: 107 kJ mol^-1

Melting point: 232 K

Boiling point: 2623 K

used since at least the bronze age and mentioned in the Old Testament

Lead

Atomic configuration: [Xe] 4f¹⁴5d¹⁰6s²6p¹

Atomic mass: 207.2

Pauling electronegativity: 1.9

Common oxidation states: +2, +4

Ionization energy: 715 kJ mol^-1

Electron affinity: 35 kJ mol^-1

Melting point: 327 K

Boiling point: 1751 K

used since at least the bronze age and mentioned in the Old Testament

Ununquadium

Atomic configuration: [Rn] 5f¹⁴6d¹⁰7s²7p¹

Atomic mass: (289)

Pauling electronegativity: -

Common oxidation states: -

Ionization energy: -

Electron affinity: -

Melting point: -

Boiling point: -

ONE atom made at the Nuclear Institute in Dubna in Russia in 1998

The pnicogens

elements with three electrons missing from a noble gas configuration

Nitrogen

Atomic configuration: [He] 2s²2p³

Atomic mass: 14.007

Pauling electronegativity: 3.0

Common oxidation states: ±3, +5

Ionization energy: 1402 kJ mol^-1

Electron affinity: 17 kJ mol^-1

Melting point: 63 K

Boiling point: 77 K

discovered in 1772 by Rutherford removing oxygen from air by combustion

Phosphorus

Atomic configuration: [Ne] 3s²3p³

Atomic mass: 30.974

Pauling electronegativity: 2.1

Common oxidation states: ±3, +5

Ionization energy: 1012 kJ mol^-1

Electron affinity: 720 kJ mol^-1

Melting point: 317 K

Boiling point: 550 K

isolated in 1669 by alchemist Brandt putrifying and distilling urine

Arsenic

Atomic configuration: [Ar] 3d¹⁰4s²4p³

Atomic mass: 74.922

Pauling electronegativity: 2.0

Common oxidation states: +3, +5

Ionization energy: 947 kJ mol^-1

Electron affinity: 78 kJ mol^-1

Melting point: sublimes at atmospheric pressure

Boiling point: 887 K

known to physicians & poisoners since at least the 5th Century BC

Antimony

Atomic configuration: [Kr] 4d¹⁰5s²5p³

Atomic mass: 121.75

Pauling electronegativity: 1.9

Common oxidation states: +3, +5

Ionization energy: 834 kJ mol^-1

Electron affinity: 103 kJ mol^-1

Melting point: 904 K

Boiling point: 1860 K

known since antiquity and probably isolated in 1492 by Benedictine monk Valentine

Bismuth

Atomic configuration: [Xe] 4f¹⁴5d¹⁰6s²6p³

Atomic mass: 208.980

Pauling electronegativity: 1.9

Common oxidation states: +3 ,+5

Ionization energy: 703 kJ mol^-1

Electron affinity: 91 kJ mol^-1

Melting point: 544 K

Boiling point: 1837 K

known to alchemists by 1480 and probably well before

The chalcogens

elements with two electrons missing from a noble gas configuration

Oxygen

Atomic configuration: [He] 2s²2p⁴

Atomic mass: 15.998

Pauling electronegativity: 3.5

Common oxidation states: ±2

Ionization energy: 1314 kJ mol^-1

Electron affinity: 141 kJ mol^-1

Melting point: 55 K

Boiling point: 90 K

discovered in 1773-4 by Scheele and Priestly but probably identified earlier

Sulfur

Atomic configuration: [Ne] 3s²3p⁴

Atomic mass: 32.06

Pauling electronegativity: 2.5

Common oxidation states: ±2, +4, +6

Ionization energy: 999 kJ mol^-1

Electron affinity: 200 kJ mol^-1

Melting point: 388 K

Boiling point: 718 K

known since prehistory and mentioned in the Bible, by Homer, Pliny and others

Selenium

Atomic configuration: [Ar] 3d¹⁰4s²4p⁴

Atomic mass: 78.96

Pauling electronegativity: 2.4

Common oxidation states: ±2, +4, +6

Ionization energy: 941 kJ mol^-1

Electron affinity: 195 kJ mol^-1

Melting point: 494 K

Boiling point: 958 K

discovered in 1872 by Berzelius and Gahn 35 years after discovery of Te

Tellurium

Atomic configuration: [Kr] 4d¹⁰5s²5p⁴

Atomic mass: 127.60

Pauling electronegativity: 2.1

Common oxidation states: ±2, +4, +6

Ionization energy: 869 kJ mol^-1

Electron affinity: 190 kJ mol^-1

Melting point: 723 K

Boiling point: 1261 K

isolated in 1782 by M�ller von Reichenstein from Transylvania ores

Pollonium

Atomic configuration: [Xe] 4f¹⁴5d¹⁰6s²6p⁴

Atomic mass: (209)

Pauling electronegativity: 2.0

Common oxidation states: ±2, +4, +6

Ionization energy: 813 kJ mol^-1

Electron affinity: 183 kJ mol^-1

Melting point: 527 K

Boiling point: 1253 K

discovered in 1898 by Marie Curie by processing uranium ore

Ununhexium

Atomic configuration: [Rn] 5f¹⁴6d¹⁰7s²7p⁴

Atomic mass: (289)

Pauling electronegativity: -

Common oxidation states: -

Ionization energy: -

Electron affinity: -

Melting point: -

Boiling point: -

observed by team at Berkeley in 1999 from decay of Uuo-118

The halogens

elements with one electron missing from a noble gas configuration

Fluorine

Atomic configuration: [He] 2s²2p⁵

Atomic mass: 18.998

Pauling electronegativity: 3.98

Common oxidation states: -1

Ionization energy: 1681 kJ mol^-1

Electron affinity: 333 kJ mol^-1

Melting point: 54 K

Boiling point: 85 K

known since antiquity and isolated in 1886 by Moissan by electrolysis

Chlorine

Atomic configuration: [Ne] 3s²3p⁵

Atomic mass: 35.453

Pauling electronegativity: 3.16

Common oxidation states: ±,+3,+5,+7

Ionization energy: 1256 kJ mol^-1

Electron affinity: 349 kJ mol^-1

Melting point: 172 K

Boiling point: 239 K

known since antiquity and isolated in 1774 by Scheele by oxidizing HCl

Bromine

Atomic configuration: [Ar] 3d¹⁰4s²5p⁵

Atomic mass: 79.904

Pauling electronegativity: 2.96

Common oxidation states: ±,+3,+5,+7

Ionization energy: 1143 kJ mol^-1

Electron affinity: 325 kJ mol^-1

Melting point: 266 K

Boiling point: 332 K

known since antiquity and isolated in 1826 by Balard from salt marsh water

Iodine

Atomic configuration: [Kr] 4d¹⁰5s²5p⁵

Atomic mass: 126.905

Pauling electronegativity: 2.66

Common oxidation states: ±,+3,+5,+7

Ionization energy: 1009 kJ mol^-1

Electron affinity: 295 kJ mol^-1

Melting point: 387 K

Boiling point: 457 K

isolated by Courtois in 1811 by treating the ash of seaweed with acid

astatine

Atomic configuration: [Xe] 4f¹⁴5d¹⁰6s²6p⁵

Atomic mass: (210)

Pauling electronegativity: 2.2

Common oxidation states: ±,+3,+5,+7

Ionization energy: ~926 kJ mol^-1

Electron affinity: ~270 kJ mol^-1

Melting point: 575 K

Boiling point: -

made by Corson, Mackenzie and Segr� in 1940 from ²⁰⁹Bi

Helium

Atomic configuration: 1s²

Atomic mass: 4.0026

Pauling electronegativity: n.a.

Common oxidation states: 0

Ionization energy: 2372 kJ mol^-1

Electron affinity: 0

Melting point: cannot be frozen at atmospheric pressure

Boiling point: 4.2 K

identified in the solar chromosphere in 1868 by Lockyer and Frankland

Neon

Atomic configuration: [He] 2s²2p⁶

Atomic mass: 20.179

Pauling electronegativity: n.a.

Common oxidation states: 0

Ionization energy: 2080 kJ mol^-1

Electron affinity: 0

Melting point: 25 K

Boiling point: 27 K

isolated by distillation of air by Ramsay and Travers in 1898

Argon

Atomic configuration: [Ne] 3s²3p⁶

Atomic mass: 39.948

Pauling electronegativity: n.a.

Common oxidation states: 0

Ionization energy: 1520 kJ mol^-1

Electron affinity: 0

Melting point: 84 K

Boiling point: 87 K

isolated by Ramsay in 1895 from atmospheric nitrogen by adding Mg

Krypton

Atomic configuration: [Ar] 4s²4p⁶

Atomic mass: 83.80

Pauling electronegativity: 3.0

Common oxidation states: 0,+2

Ionization energy: 1351 kJ mol^-1

Electron affinity: 0

Melting point: 116 K

Boiling point: 120 K

isolated by distillation of air by Ramsay and Travers in 1898

Xenon

Atomic configuration: [Kr] 5s²5p⁶

Atomic mass: 131.29

Pauling electronegativity: 2.6

Common oxidation states: 0,+2,+4,+6

Ionization energy: 1170 kJ mol^-1

Electron affinity: 0

Melting point: 161 K

Boiling point: 165 K

isolated by distillation of air by Ramsay and Travers in 1898

Radon

Atomic configuration: [Xe] 6s²6p⁶

Atomic mass: (222)

Pauling electronegativity: n.a.

Common oxidation states: 0

Ionization energy: 1037 kJ mol^-1

Electron affinity: 0

Melting point: 202 K

Boiling point: 211 K

observed as a short-lived radioactive element in 1902 by Rutherford and Soddy

Ununoctium

Atomic configuration: [Rn] s²7p⁶

Atomic mass: -

Pauling electronegativity: -

Common oxidation states: -

Ionization energy: -

Electron affinity: -

Melting point: -

Boiling point: -

claimed in 1999 by team at Berkeley but withdrawn in 2001

Cerium

Atomic configuration: [Xe] 6s²4f¹5d¹

Atomic mass: 140.12

Pauling electronegativity: 1.12

Common oxidation states: +3, +4

Ionization energy: 541 kJ mol^-1

Electron affinity: -

Melting point: 798 K

Boiling point: 3433 K

isolated in 1839 by the Swedish surgeon Mosander from the mineral ceria

Praseodymium

Atomic configuration: [Xe] 6s²4f³

Atomic mass: 140.91

Pauling electronegativity: 1.13

Common oxidation states: +3, +4

Ionization energy: 522 kJ mol^-1

Electron affinity: -

Melting point: 931 K

Boiling point: 3520 K

isolated in 1885 by von Welsbach from the mineral ceria

Neodymium

Atomic configuration: [Xe] 6s²4f⁴

Atomic mass: 144.24

Pauling electronegativity: 1.14

Common oxidation states: +2, +3, +4

Ionization energy: 530 kJ mol^-1

Electron affinity: -

Melting point: 1021 K

Boiling point: 3074 K

isolated in 1885 by von Welsbach from the mineral ceria

Promethium

Atomic configuration: [Xe] 6s²4f⁵

Atomic mass: -

Pauling electronegativity: -

Common oxidation states: +3

Ionization energy: 536 kJ mol^-1

Electron affinity: -

Melting point: 1042 K

Boiling point: ~3000 K

first seen in 1947 by Marinsky, Glendenin and Coryell in U fission products

Samarium

Atomic configuration: [Xe] 6s²4f⁶

Atomic mass: 150.36

Pauling electronegativity: 1.17

Common oxidation states: +2, +3

Ionization energy: 542 kJ mol^-1

Electron affinity: -

Melting point: 1345 K

Boiling point: 2076 K

isolated in 1879 by de Boisbaudram from the mineral ceria

Europium

Atomic configuration: [Xe] 6s²4f⁷

Atomic mass: 151.96

Pauling electronegativity: -

Common oxidation states: +2, +3

Ionization energy: 547 kJ mol^-1

Electron affinity: -

Melting point: 822 K

Boiling point: 1794 K

isolated in 1901 by Demarcay from the mineral ceria

Gadolinium

Atomic configuration: [Xe] 6s²4f⁷5d¹

Atomic mass: 157.25

Pauling electronegativity: 1.20

Common oxidation states: +3

Ionization energy: 595 kJ mol^-1

Electron affinity: -

Melting point: 1313 K

Boiling point: 3273 K

isolated in 1880 by de Marignac from the mineral yttria

Terbium

Atomic configuration: [Xe] 6s²4f⁹

Atomic mass: 158.93

Pauling electronegativity: -

Common oxidation states: +3, +4

Ionization energy: 569 kJ mol^-1

Electron affinity: -

Melting point: 1365 K

Boiling point: 3230 K

isolated in 1843 by the Swedish surgeon Mosander from the mineral yttria

Dysprosium

Atomic configuration: [Xe] 6s²4f¹⁰

Atomic mass: 162.50

Pauling electronegativity: 1.22

Common oxidation states: +2, +3, +4

Ionization energy: 567 kJ mol^-1

Electron affinity: -

Melting point: 1412 K

Boiling point: 2567 K

isolated in 1886 by de Boisbaudran from the mineral yttria

Holmium

Atomic configuration: [Xe] 6s²4f¹¹

Atomic mass: 164.93

Pauling electronegativity: 1.23

Common oxidation states: +3

Ionization energy: 574 kJ mol^-1

Electron affinity: -

Melting point: 1474 K

Boiling point: 2700 K

isolated in 1878 by Soret and Delafontaine from the mineral yttria

Erbium

Atomic configuration: [Xe] 6s²4f¹²

Atomic mass: 167.26

Pauling electronegativity: 1.24

Common oxidation states: +3

Ionization energy: 581 kJ mol^-1

Electron affinity: -

Melting point: 1529 K

Boiling point: 2868 K

isolated in 1843 by Carl Mosander from the mineral yttria

Thullium

Atomic configuration: [Xe] 6s²4f¹³

Atomic mass: 168.93

Pauling electronegativity: 1.25

Common oxidation states: +2, +3

Ionization energy: 589 kJ mol^-1

Electron affinity: -

Melting point: 1545 K

Boiling point: 1950 K

isolated in 1879 by Per Theodore Cleve from the mineral yttria

Ytterbium

Atomic configuration: [Xe] 6s²4f¹⁴

Atomic mass: 173.04

Pauling electronegativity: -

Common oxidation states: +2, +3

Ionization energy: 603 kJ mol^-1

Electron affinity: -

Melting point: 819 K

Boiling point: 1196 K

isolated in 1878 by de Marignac from the mineral yttria

Lutetium

Atomic configuration: [Xe] 6s²4f¹⁴5d¹

Atomic mass: 174.97

Pauling electronegativity: 1.27

Common oxidation states: +3

Ionization energy: 513 kJ mol^-1

Electron affinity: -

Melting point: 1663 K

Boiling point: 3402 K

isolated (1907) by Urbain/James/von Welsbach from yttria

Thorium

Atomic configuration: [Rn] 7s²6d²

Atomic mass: 232.4

Pauling electronegativity: 1.3

Common oxidation states: +3, +4

Ionization energy: 587 kJ mol^-1

Electron affinity: -

Melting point: 1750 K

Boiling point: 4788 K

isolated in 1828 by J. J. Berzelius from the mineral now known as thorite

Protactinium

Atomic configuration: [Rn] 7s²5f²6d¹

Atomic mass: 231.04

Pauling electronegativity: 1.5

Common oxidation states: +3, +4, +5

Ionization energy: 568 kJ mol^-1

Electron affinity: -

Melting point: 1572 K

Boiling point: (4720 K)

identified in 1913 by Fajans and Gohring in ²³⁸U decay series

Uranium

Atomic configuration: [Rn] 7s²5f³6d¹

Atomic mass: 238.04

Pauling electronegativity: 1.38

Common oxidation states: +2, +3, +4, +5, +6

Ionization energy: 598 kJ mol^-1

Electron affinity: -

Melting point: 1135 K

Boiling point: 3818 K

identified and isolated in 1789 by M. H. Klaproth in pitchblende

Neptunium

Atomic configuration: [Rn] 7s²5f⁴6d¹

Atomic mass: 237.05

Pauling electronegativity: 1.36

Common oxidation states: +3, +4, +5, +6, +7

Ionization energy: 585 kJ mol^-1

Electron affinity: -

Melting point: 644 K

Boiling point: (3900 K)

made in 1940 by McMillan and Abelson by neutron bombardment of ²³⁸U

Plutonium

Atomic configuration: [Rn] 7s²5f⁶

Atomic mass: (244)

Pauling electronegativity: 1.28

Common oxidation states: +3, +4, +5, +6, +7

Ionization energy: 605 kJ mol^-1

Electron affinity: -

Melting point: 640 K

Boiling point: 328 K

made in 1940 by Seaborg, McMillan, Kennedy and Wahl from ²³⁸U

Americium

Atomic configuration: [Rn] 7s²5f⁷

Atomic mass: (243)

Pauling electronegativity: 1.3

Common oxidation states: +3, +4, +5, +6

Ionization energy: 578 kJ mol^-1

Electron affinity: -

Melting point: 1176 K

Boiling point: (2600 K)

made in 1944 by Seaborg, James, Morgan and Ghiorso from ²³⁹Pu

Curium

Atomic configuration: [Rn] 7s²5f⁷6d¹

Atomic mass: (247)

Pauling electronegativity: 1.3

Common oxidation states: +3, +4

Ionization energy: 581 kJ mol^-1

Electron affinity: -

Melting point: 1345 K

Boiling point: -

made in 1944 by Seaborg, James and Ghiorso from ²³⁹Pu

Berkelium

Atomic configuration: [Rn] 7s²5f⁸6d¹

Atomic mass: (247)

Pauling electronegativity: 1.3

Common oxidation states: +3, +4

Ionization energy: 601 kJ mol^-1

Electron affinity: -

Melting point: 1050 K

Boiling point: -

made in 1949 by Seaborg, Ghiorso and Thompson from ²⁴¹Am

Californium

Atomic configuration: [Rn] 7s²5f¹⁰

Atomic mass: (251)

Pauling electronegativity: 1.3

Common oxidation states: +3, +4

Ionization energy: 608 kJ mol^-1

Electron affinity: -

Melting point: 900 K

Boiling point: -

made in 1944 by Street/ Seaborg/ James / Ghiorso from ²⁴²Cm

Einsteinium

Atomic configuration: [Rn] 7s²5f¹¹

Atomic mass: (252)

Pauling electronegativity: 1.3

Common oxidation states: +3

Ionization energy: 619 kJ mol^-1

Electron affinity: -

Melting point: 860 K

Boiling point: -

identifed in 1952 at Berkeley in thermonuclear explosion debris

Fermium

Atomic configuration: [Rn] 7s²5f¹²

Atomic mass: (257)

Pauling electronegativity: 1.3

Common oxidation states: +3

Ionization energy: 627 kJ mol^-1

Electron affinity: -

Melting point: 1527 K

Boiling point: -

identifed in 1952 at Berkeley in thermonuclear explosion debris

Mendelevium

Atomic configuration: [Rn] 7s²5f¹³

Atomic mass: (258)

Pauling electronegativity: 1.3

Common oxidation states: +3

Ionization energy: 635 kJ mol^-1

Electron affinity: -

Melting point: 827 K

Boiling point: -

made in 1955 by Seaborg, Ghiorso, Harvey, Choppin and Thompson from ²⁵³Es

Nobelium

Atomic configuration: [Rn] 7s²5f¹⁴

Atomic mass: (259)

Pauling electronegativity: 1.3

Common oxidation states: +2, +3

Ionization energy: 642 kJ mol^-1

Electron affinity: -

Melting point: 827 K

Boiling point: -

made in 1956 at Dubna from ¹⁵N bombardment of ²⁴³Am

Lawrencium

Atomic configuration: [Rn] 7s²5f¹⁴6d¹

Atomic mass: (260)

Pauling electronegativity: 1.3

Common oxidation states: +3

Ionization energy: -

Electron affinity: -

Melting point: 1627 K

Boiling point: -

made in 1961-71 at Berkeley and Dubna from Cf and ²⁴³Am