No. Atomic Name Sym M.P. B.P. Density* Earth (founded) Group* Electron Ionization
Weight (°C) (°C) (g/cm3) crust% (Year) config energy (eV)



1 1.0079 Hydrogen H -259 -253 0.09 0.14 1776 1 1s1 13.5984
2 4.0026 Helium He -272 -269 0.18 1895 18 1s2 24.5874
3 6.941 Lithium Li 180 1347 0.53 1817 1 [He] 2s1 5.3917
4 9.0122 Beryllium Be 1278 2970 1.85 1797 2 [He] 2s2 9.3227
5 10.811 Boron B 2300 2550 2.34 1808 13 [He] 2s2 2p1 8.298
6 12.0107 Carbon C 3500 4827 2.26 0.094 ancient 14 [He] 2s2 2p2 11.2603
7 14.0067 Nitrogen N -210 -196 1.25 1772 15 [He] 2s2 2p3 14.5341
8 15.9994 Oxygen O -218 -183 1.43 46.71 1774 16 [He] 2s2 2p4 13.6181
9 18.9984 Fluorine F -220 -188 1.7 0.029 1886 17 [He] 2s2 2p5 17.4228
10 20.1797 Neon Ne -249 -246 0.9 1898 18 [He] 2s2 2p6 21.5645
11 22.9897 Sodium Na 98 883 0.97 2.75 1807 1 [Ne] 3s1 5.1391
12 24.305 Magnesium Mg 639 1090 1.74 2.08 1755 2 [Ne] 3s2 7.6462
13 26.9815 Aluminum Al 660 2467 2.7 8.07 1825 13 [Ne] 3s2 3p1 5.9858
14 28.0855 Silicon Si 1410 2355 2.33 27.69 1824 14 [Ne] 3s2 3p2 8.1517
15 30.9738 Phosphorus P 44 280 1.82 0.13 1669 15 [Ne] 3s2 3p3 10.4867
16 32.065 Sulfur S 113 445 2.07 0.052 ancient 16 [Ne] 3s2 3p4 10.36
17 35.453 Chlorine Cl -101 -35 3.21 0.045 1774 17 [Ne] 3s2 3p5 12.9676
18 39.948 Argon Ar -189 -186 1.78 1894 18 [Ne] 3s2 3p6 15.7596
19 39.0983 Potassium K 64 774 0.86 2.58 1807 1 [Ar] 4s1 4.3407
20 40.078 Calcium Ca 839 1484 1.55 3.65 1808 2 [Ar] 4s2 6.1132
21 44.9559 Scandium Sc 1539 2832 2.99 1879 3 [Ar] 3d1 4s2 6.5615
22 47.867 Titanium Ti 1660 3287 4.54 0.62 1791 4 [Ar] 3d2 4s2 6.8281
23 50.9415 Vanadium V 1890 3380 6.11 1830 5 [Ar] 3d3 4s2 6.7462
24 51.9961 Chromium Cr 1857 2672 7.19 0.035 1797 6 [Ar] 3d5 4s1 6.7665
25 54.938 Manganese Mn 1245 1962 7.43 0.09 1774 7 [Ar] 3d5 4s2 7.434
26 55.845 Iron Fe 1535 2750 7.87 5.05 ancient 8 [Ar] 3d6 4s2 7.9024
27 58.9332 Cobalt Co 1495 2870 8.9 1735 9 [Ar] 3d7 4s2 7.881
28 58.6934 Nickel Ni 1453 2732 8.9 0.019 1751 10 [Ar] 3d8 4s2 7.6398
29 63.546 Copper Cu 1083 2567 8.96 ancient 11 [Ar] 3d10 4s1 7.7264
30 65.39 Zinc Zn 420 907 7.13 ancient 12 [Ar] 3d10 4s2 9.3942
31 69.723 Gallium Ga 30 2403 5.91 1875 13 [Ar] 3d10 4s2 4p1 5.9993
32 72.64 Germanium Ge 937 2830 5.32 1886 14 [Ar] 3d10 4s2 4p2 7.8994
33 74.9216 Arsenic As 81 613 5.72 ancient 15 [Ar] 3d10 4s2 4p3 9.7886
34 78.96 Selenium Se 217 685 4.79 1817 16 [Ar] 3d10 4s2 4p4 9.7524
35 79.904 Bromine Br -7 59 3.12 1826 17 [Ar] 3d10 4s2 4p5 11.8138
36 83.8 Krypton Kr -157 -153 3.75 1898 18 [Ar] 3d10 4s2 4p6 13.9996
37 85.4678 Rubidium Rb 39 688 1.63 1861 1 [Kr] 5s1 4.1771
38 87.62 Strontium Sr 769 1384 2.54 1790 2 [Kr] 5s2 5.6949
39 88.9059 Yttrium Y 1523 3337 4.47 1794 3 [Kr] 4d1 5s2 6.2173
40 91.224 Zirconium Zr 1852 4377 6.51 0.025 1789 4 [Kr] 4d2 5s2 6.6339
41 92.9064 Niobium Nb 2468 4927 8.57 1801 5 [Kr] 4d4 5s1 6.7589
42 95.94 Molybdenum Mo 2617 4612 10.22 1781 6 [Kr] 4d5 5s1 7.0924
43 * 98 Technetium Tc 2200 4877 11.5 1937 7 [Kr] 4d5 5s2 7.28
44 101.07 Ruthenium Ru 2250 3900 12.37 1844 8 [Kr] 4d7 5s1 7.3605
45 102.9055 Rhodium Rh 1966 3727 12.41 1803 9 [Kr] 4d8 5s1 7.4589
46 106.42 Palladium Pd 1552 2927 12.02 1803 10 [Kr] 4d10 8.3369
47 107.8682 Silver Ag 962 2212 10.5 ancient 11 [Kr] 4d10 5s1 7.5762
48 112.411 Cadmium Cd 321 765 8.65 1817 12 [Kr] 4d10 5s2 8.9938
49 114.818 Indium In 157 2000 7.31 1863 13 [Kr] 4d10 5s2 5p1 5.7864
50 118.71 Tin Sn 232 2270 7.31 ancient 14 [Kr] 4d10 5s2 5p2 7.3439
51 121.76 Antimony Sb 630 1750 6.68 ancient 15 [Kr] 4d10 5s2 5p3 8.6084
52 127.6 Tellurium Te 449 990 6.24 1783 16 [Kr] 4d10 5s2 5p4 9.0096
53 126.9045 Iodine I 114 184 4.93 1811 17 [Kr] 4d10 5s2 5p5 10.4513
54 131.293 Xenon Xe -112 -108 5.9 1898 18 [Kr] 4d10 5s2 5p6 12.1298
55 132.9055 Cesium Cs 29 678 1.87 1860 1 [Xe] 6s1 3.8939
56 137.327 Barium Ba 725 1140 3.59 0.05 1808 2 [Xe] 6s2 5.2117
57 138.9055 Lanthanum La 920 3469 6.15 1839 3 [Xe] 5d1 6s2 5.5769
58 140.116 Cerium Ce 795 3257 6.77 1803 101 [Xe] 4f1 5d1 6s2 5.5387
59 140.9077 Praseodymium Pr 935 3127 6.77 1885 101 [Xe] 4f3 6s2 5.473
60 144.24 Neodymium Nd 1010 3127 7.01 1885 101 [Xe] 4f4 6s2 5.525
61 * 145 Promethium Pm 1100 3000 7.3 1945 101 [Xe] 4f5 6s2 5.582
62 150.36 Samarium Sm 1072 1900 7.52 1879 101 [Xe] 4f6 6s2 5.6437
63 151.964 Europium Eu 822 1597 5.24 1901 101 [Xe] 4f7 6s2 5.6704
64 157.25 Gadolinium Gd 1311 3233 7.9 1880 101 [Xe] 4f7 5d1 6s2 6.1501
65 158.9253 Terbium Tb 1360 3041 8.23 1843 101 [Xe] 4f9 6s2 5.8638
66 162.5 Dysprosium Dy 1412 2562 8.55 1886 101 [Xe] 4f10 6s2 5.9389
67 164.9303 Holmium Ho 1470 2720 8.8 1867 101 [Xe] 4f11 6s2 6.0215
68 167.259 Erbium Er 1522 2510 9.07 1842 101 [Xe] 4f12 6s2 6.1077
69 168.9342 Thulium Tm 1545 1727 9.32 1879 101 [Xe] 4f13 6s2 6.1843
70 173.04 Ytterbium Yb 824 1466 6.9 1878 101 [Xe] 4f14 6s2 6.2542
71 174.967 Lutetium Lu 1656 3315 9.84 1907 101 [Xe] 4f14 5d1 6s2 5.4259
72 178.49 Hafnium Hf 2150 5400 13.31 1923 4 [Xe] 4f14 5d2 6s2 6.8251
73 180.9479 Tantalum Ta 2996 5425 16.65 1802 5 [Xe] 4f14 5d3 6s2 7.5496
74 183.84 Tungsten W 3410 5660 19.35 1783 6 [Xe] 4f14 5d4 6s2 7.864
75 186.207 Rhenium Re 3180 5627 21.04 1925 7 [Xe] 4f14 5d5 6s2 7.8335
76 190.23 Osmium Os 3045 5027 22.6 1803 8 [Xe] 4f14 5d6 6s2 8.4382
77 192.217 Iridium Ir 2410 4527 22.4 1803 9 [Xe] 4f14 5d7 6s2 8.967
78 195.078 Platinum Pt 1772 3827 21.45 1735 10 [Xe] 4f14 5d9 6s1 8.9587
79 196.9665 Gold Au 1064 2807 19.32 ancient 11 [Xe] 4f14 5d10 6s1 9.2255
80 200.59 Mercury Hg -39 357 13.55 ancient 12 [Xe] 4f14 5d10 6s2 10.4375
81 204.3833 Thallium Tl 303 1457 11.85 1861 13 [Xe] 4f14 5d10 6s2 6p1 6.1082
82 207.2 Lead Pb 327 1740 11.35 ancient 14 [Xe] 4f14 5d10 6s2 6p2 7.4167
83 208.9804 Bismuth Bi 271 1560 9.75 ancient 15 [Xe] 4f14 5d10 6s2 6p3 7.2856
84 * 209 Polonium Po 254 962 9.3 1898 16 [Xe] 4f14 5d10 6s2 6p4 8.417
85 * 210 Astatine At 302 337 1940 17 [Xe] 4f14 5d10 6s2 6p5 9.3
86 * 222 Radon Rn -71 -62 9.73 1900 18 [Xe] 4f14 5d10 6s2 6p6 10.7485
87 * 223 Francium Fr 27 677 1939 1 [Rn] 7s1 4.0727
88 * 226 Radium Ra 700 1737 5.5 1898 2 [Rn] 7s2 5.2784
89 * 227 Actinium Ac 1050 3200 10.07 1899 3 [Rn] 6d1 7s2 5.17
90 232.0381 Thorium Th 1750 4790 11.72 1829 102 [Rn] 6d2 7s2 6.3067
91 231.0359 Protactinium Pa 1568 15.4 1913 102 [Rn] 5f2 6d1 7s2 5.89
92 238.0289 Uranium U 1132 3818 18.95 1789 102 [Rn] 5f3 6d1 7s2 6.1941
93 * 237 Neptunium Np 640 3902 20.2 1940 102 [Rn] 5f4 6d1 7s2 6.2657
94 * 244 Plutonium Pu 640 3235 19.84 1940 102 [Rn] 5f6 7s2 6.0262
95 * 243 Americium Am 994 2607 13.67 1944 102 [Rn] 5f7 7s2 5.9738
96 * 247 Curium Cm 1340 13.5 1944 102 5.9915
97 * 247 Berkelium Bk 986 14.78 1949 102 6.1979
98 * 251 Californium Cf 900 15.1 1950 102 6.2817
99 * 252 Einsteinium Es 860 1952 102 6.42
100 * 257 Fermium Fm 1527 1952 102 6.5
101 * 258 Mendelevium Md 1955 102 6.58
102 * 259 Nobelium No 827 1958 102 6.65
103 * 262 Lawrencium Lr 1627 1961 102 4.9
104 * 261 Rutherfordium Rf 1964 4
105 * 262 Dubnium Db 1967 5
106 * 266 Seaborgium Sg 1974 6
107 * 264 Bohrium Bh 1981 7
108 * 277 Hassium Hs 1984 8
109 * 268 Meitnerium Mt 1982 9










Abbreviations and Definitions:
No. - Atomic Number
M.P. - melting point
B.P. - boiling point
* Density of elements with boiling points below 0°C is given in g/l and in sorted list they are shown before other elements with boling point >0°C.
* Earth crust composition average values are from a report by F. W. Clarke and H. S. Washington, 1924. Elemental composition of crustal rocks differ between different localities (see article).
* Group: There are only 18 groups in the periodic table that constitute the columns of the table. Lanthanoids and Actinoids are numbered as 101 and 102 to separate them in sorting by group.

Atomic number: The number of protons in an atom. Each element is uniquely defined by its atomic number.

Atomic mass: The mass of an atom is primarily determined by the number of protons and neutrons in its nucleus. Atomic mass is measured in Atomic Mass Units (amu) which are scaled relative to carbon, 12C, that is taken as a standard element with an atomic mass of 12. This isotope of carbon has 6 protons and 6 neutrons. Thus, each proton and neutron has a mass of about 1 amu.

Isotope: Atoms of the same element with the same atomic number, but different number of neutrons. Isotope of an element is defined by the sum of the number of protons and neutrons in its nucleus. Elements have more than one isotope with varying numbers of neutrons. For example, there are two common isotopes of carbon, 12C and 13C which have 6 and 7 neutrons respectively. The abundances of different isotopes of elements vary in nature depending on the source of materials. For relative abundances of isotopes in nature see reference on Atomic Weights and Isotopic Compositions.

Atomic weight: Atomic weight values represent weighted average of the masses of all naturally occurring isotopes of an element. The values shown here are based on the IUPAC Commission determinations (Pure Appl. Chem. 73:667-683, 2001). The elements marked with an asterisk have no stable nuclides. For these elements the weight value shown represents the mass number of the longest-lived isotope of the element.

Electron configuration: The distribution of electrons according to the energy sublevels (subshells) in uncharged atoms. The noble gas shown in square brackets (e.g. [He]), marks that all the subshells associated with that element are fully occupied by electrons.
Energy levels and sublevels Principal energy level
(Quantum number: n) Sublevels available
(Quantum number: l)
1
2
3
4
5
6 1s
2s 2p
3s 3p 3d
4s 4p 4d 4f
5s 5p 5d 5f 5g
6s 6p 6d 6f 6g 6h

Ionization energy (IE): The energy required to remove the outermost electron from an atom or a positive ion in its ground level. The table lists only the first IE in eV units. To convert to kJ/mol multiply by 96.4869. Reference: NIST Reference Table on Ground states and ionization energies for the neutral atoms. IE decreases going down a column of the periodic table, and increases from left to right in a row. Thus, alkali metals have the lowest IE in a period and Rare gases have the highest.