Atomic  Symbol     Element  Relative  atomic  Abundance   Melting   Boiling  Date of  First ionisation First electron Electronegativity Enthalpy of  Density
number mass      /ppm  point /K   point /K  discovery energy / kJ mol-1 affinity / kJ mol-1 (Aldred Rochow) atomisation / kJ mol-1 / kg m-3
1 H  Hydrogen 1.01 1,520.00                        14                       20 1766 1312 72.8 2.20*
2 He  Helium 4.00 0.00                           1                          4 1895 2372 ‑ 21 (calc.) n.a.
3 Li  Lithium 6.94 18.00                      454                 1,620 1817 513 59.8 0.97
4 Be  Beryllium 9.01 2.00                  1,551                 3,243 1797 899 ‑18 1.47
5 B  Boron 10.81 9.00                  2,573                 3,931 1808 801 23 2.01
6 C  Carbon 12.01 180.00                  3,820  *5,100  pre-history 1086 122.5 2.50
7 N  Nitrogen 14.01 19.00                        63                       77 1772 1402 ‑7 3.07
8 O  Oxygen 16.00 455,000.00                        55                       90 1774 1314 141 3.50
9 F  Fluorine 19.00 544.00                        54                       85 1886 1681 322 4.10
10 Ne  Neon 20.18 0.04                        24                       27 1898 2081 ‑ 29 (calc.) na.
11 Na  Sodium 22.99 22,700.00                      371                 1,156 1807 496 52.9 1.08
12 Mg  Magnesium 24.31 27,640.00                      922                 1,363 1755 738 ‑21 1.23
13 Al  Aluminium 26.98 83,000.00                      934                 2,740 1825 577 44 1.47
14 Si  Silicon 28.09 272,000.00                  1,683                 2,628 1824 787 133.6 1.74
15 P  Phosphorus 30.97 1,120.00                      317                     553 1669 1012 71.7 2.06
16 S  Sulfur 32.06 340.00                      386                     718 pre-history 1000 200.4 2.44
17 CI  Chlorine 35.45 126.00                      172                     239 1774 1251 348.7 2.83
18 Ar  Argon 39.95 0.04                        84                       87 1894 1520 ‑ 3 5 (calc.) n.a.
19 K  Potassium 39.10 18,400.00                      337                 1,047 1807 419 43.8 0.91
20 Ca  Calcium 40.08 46,600.00                  1,112                 1,757 1808 590 ‑186 1.04
21 Sc  Scandium 44.96 25.00                  1,814                 3,104 1879 631 ‑70 1.20
22 Ti  Titanium 47.90 6,320.00                  1,933                 3,560 1791 658 ‑2 1.32
23 V  Vanadium 50.94 136.00                  2,160                 3,650 1801 650 61 1.45
24 Cr  Chromium 52.00 122.00                  2,130                 2,945 1780 653 94 1.56
25 Mn  Manganese 54.94 1,060.00                  1,517                 2,235 1774 717 ‑94 1.60
26 Fe  Iron 55.85 62,000.00                  1,808                 3,023 c. 2500 BC 759 44 1.64
27 Co  Cobalt 58.93 29.00                  1,768                 3,143 1735 760 102 1.70
28 Ni Nickel 58.70 99.00                  1,726                 3,005 1751 737 156 1.75
29 Cu  Copper 63.55 68.00                  1,357                 2,840 c. 5000 BC 745 118.3 1.75
30 Zn  Zinc 65.38 76.00                      693                 1,180 Pre 1500* 906 9 1.66
31 Ga Gallium 69.74 19.00                      303                 2,676 1875 579 36 (calc.) 1.82
32 Ge  Germanium 72.59 1.50                  1,211                 3,103 1896 762 116 2.02
33 As  Arsenic 74.92 1.80                  1,090  *889  c. 1250 947 77 2.20
34 Se  Selenium 78.96 0.05                      490                     958 1817 941 195 2.48
35 Br  Bromine 79.90 2.50                      266                     332 1826 1140 324.5 2.74
36 Kr  Krypton 83.80 0.00                      117                     121 1898 1351 ‑ 39 (calc.) 2.9*
37 Rb  Rubidium 85.47 78.00                      312                     961 1861 403 46.9 0.89
38 Sr  Strontium 87.62 384.00                  1,042                 1,657 1808 550 ‑146 0.99
39 Y  Yttrium 88.91 31.00                  1,795                 3,611 1794 616 ‑39 1.11
40 Zr  Zirconium 91.22 162.00                  2,125                 4,650 1789 660 43 1.22
41 Nb  Niobium 92.91 20.00                  2,741                 5,015 1801 664 109 1.23
42 Mo  Molybdenum 95.94 1.20                  2,890                 4,885 1781 685 114 1.30
43 Tc  Technetium 98 0.00                  2,445                 5,150 1937 702 96 1.36
44 Ru  Ruthenium 101.17 0.00                  2,583                 4,173 1808 711 146 1.42
45 Rh  Rhodium 102.91 0.00                  2,239                 4,000 1803 720 162 1.45
46 Pd  Palladium 106.40 0.02                  1,825                 3,413 1803 805 98.4 1.35
47 Ag  Silver 107.87 0.08                  1,235                 2,485 c. 3000 BC 731 125.7 1.42
48 Cd  Cadmium 112.41 0.16                      594                 1,038 1817 868 ‑26 1.46
49 In  Indium 114.82 0.24                      429                 2,353 1863 558 34 1.49
50 Sn  Tin 118.69 2.10                      505                 2,543 c. 2100 BC 709 121 1.72
51 Sb  Antimony 121.75 0.20                      904                 1,908 c. 1600 BC 834 101 1.82
52 Te  Tellurium 127.60 0.00                      723                 1,263 1783 869 190.2 2.01
53 I  Iodine 126.90 0.46                      387                     458 1811 1008 295.3 2.21
54 Xe  Xenon 131.30 0.00                      161                     166 1898 1170 ‑ 41 (calc.) 2.6*
55 Cs Caesium 132.91 2.60                      302                     952 1860 3757 45.5 0.86
56 Ba Barium 137.33 390.00                  1,002                 1,910 1808 503 ‑46 0.97
57 La Lanthanum 138.91 35.00                  1,194                 3,730 1839 538 53 1.08
58 Ce Cerium 140.12 66.00                  1,072                 3,699 1803 527 50 1.06
59 Pr Praseodymium 140.91 9.10                  1,204                 3,785 1885 523 50 1.07
60 Nd Neodymium 144.24 40.00                  1,294                 3,341 1885 530 50 1.07
61 Pm  Promethium 145 0.00                  1,441  est 3,000  1945 536 50 1.07
62 Sm  Samarium 150.40 7.00                  1,350                 2,064 1879 543 50 1.07
63 Eu Europium 151.96 2.10                  1,095                 1,870 1901 547 50 1.01
64 Gd Gadolinium 157.25 6.10                  1,586                 3,539 1880 593 50 1.11
65 Tb Terbium 158.93 1.20                  1,629                 3,396 1843 565 50 1.10
66 Dy Dysprosium 162.50 4.50                  1,685                 2,835 1886 572 50 1.10
67 Ho Holmium 164.93 1.30                  1,747                 2,968 1878 581 50 1.10
68 Er Erbium 167.26 3.50                  1,802                 3,136 1842 589 50 1.11
69 Tm Thulium 168.93 0.50                  1,818                 2,220 1879 597 50 1.11
70 Yb Ytterbium 173.04 3.10                  1,097                 1,466 1878 603 50 1.06
71 Lu Lutetium 174.97 0.80                  1,936                 3,668 1907 524 50 1.14
72 Hf Hafnium 178.49 2.80                  2,503                 5,470 1923 642 61 1.23
73 Ta Tantalum 180.95 1.70                  3,269                 5,698 1802 761 14 1.33
74 W Tungsten 183.85 1.20                  3,680                 5,930 1783 770 119 1.40
75 Re Rhenium 186.21 0.00                  3,453                 5,900 1925 760 37 1.46
76 Os Osmium 190.20 0.01                  3,327                 5,300 1803 840 139 1.52
77 Ir Iridium 192.22 0.00                  2,683                 4,403 1803 880 190 1.55
78 Pt Platinum 195.09 0.01                  2,045                 4,100 Pre 1700 870 247 1.44
79 Au Gold 196.97 0.00                  1,338                 3,080 c. 3000 BC 890 223 1.42
80 Hg Mercury 200.59 0.08                      234                     630 c. 1500 BC 1007 ‑18 1.44
81 Ti Thallium 204.37 0.70                      577                 1,730 1861 589 30 1.44
82 Pb Lead  207.20 13.00                      601                 2,013 c. 1000 BC 716 35.2 1.55
83 Bi Bismuth 208.98 0.01                      545                 1,883 c. 1500 703 101 1.67
84 Po Polonium 209 0.00                      527                 1,235 1898 812 186 1.76
85 At Astatine 210 0.00  est 575   est 610  1940 930 270 1.96
86 Rn Radon 222 0.00                      202                     211 1900 1037 ‑41 (calc.) c. 2.0 (est.)
87 Fr  Francium 223 0.00                      300                     950 1939 400 44 (calc.) 0.86
88 Re  Radium 226.03 0.00                      973                 1,413 1898 509 0.97
89 Ac  Actinium 227 0.00                  1,320                 3,470 1899 499 1.00
90 Th  Thorium 232.04 8.10                  2,023                 5,060 1815 587 1.11
91 Pa  Protactinium 231.04 0.00                  2,113  est 4,300  1917 568 1.14
92 U  Uranium 238.03 2.30                  1,406                 4,018 1789 584 1.22
93 Np  Neptunium 237 0.00                      913                 4,175 1940 597 1.22
94 Pu  Plutonium 244 0.00                      914                 3,505 1940 585 1.22
95 Am  Americium 243 0.00                  1,267                 2,880 1944 578
96 Cm  Curium 247 0.00  -   -  1944 581
97 Bk  Berkelium 247 0.00  -   -  1949 601
98 Cf  Californium 251 0.00  -   -  1950 608
99 Es  Einsteinium 254 0.00  -   -  1952 619
100 Fm  Fermium 257 0.00  -   -  1952 627
101 Md  Mendelevium 258 0.00  -   -  1955 635
102 No  Nobelium 259 0.00  -   -  1958 642
103 Lr  Lawrencium 260 0.00  -   -  1961 -