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The Periodic Table of Elements
 
 
To view more detailed information on each of the elements, click on the relevant section of the picture below.



 
 
 
A brief history of the periodic table

The rectangular periodic table is familiar to anybody who has ever been in a science laboratory or classroom. This ingenious functional grouping of the chemical elements was created by several European scientists in the decade of the 1860's. In 1863, French geologist, A.E.Béguyer de Chancourtois created a list of the elements arranged by increasing atomic weight. The list was wrapped around a cylinder so that several sets of similar elements lined up, creating the first geometric representation of the periodic law.

In England, analytical chemist John A.R. Newlands was also wrapping the elements, noting that chemical groups repeated every eight elements. He named this the octave rule, and compared it to a musical scale. Some less observant members of the English Chemical Society considered this absurd, so his work was ignored for years.

Chemists Dmitrii I. Mendeleev and Lothar Meyer were working independently in 1868 and 1869 on the arrangement of elements into seven columns, corresponding to various chemical and physical properties. Their tables were similar - they acknowledged each other's work - the differences are subtle but important: Meyer's table was an accurate (for the time) accounting of the known facts about each element, such as melting point and atomic volume. The table clearly showed the existence of periodic chemical families. In 1870 Meyer's table and description of the periodic law was published in Liebig's Annalen.

A year earlier however, Mendeleev presented a much more scientifically useful table. His paper, "On the Relation of the Properties to the Atomic Weights of the Elements"  was enthusiastically received by the Russian Chemical Society. In it, the periodic relationship between chemical groups is clearly illustrated. In a scientific triumph, gaps in the table accurately predicted undiscovered elements. Although Mendeleev's table is nearly 130 years old it differs little from the charts used today.

 
 
 
Elements Listed by Atomic Number

To return to the periodic table at the top of the page click on the atomic number for any of the elements
For a full description and more information on any element, click on the name to be taken to the relevant wikipedia page
 
Atomic
Number
Name Symbol Group Phase
at
298°K
Atomic
Mass
Density
(g/cm³)
at 20°C
Melting
Point °C
Boiling
Point °C
CAS(*)
Registry ID
Year
Discovered
Discoverer
1 Hydrogen H Nonmetals Gas 1.00794(7) 0.084 g/l -259.1 -252.9 13333-74-0 1766 Cavendish
2 Helium He Noble Gases Gas 4.002602(2) 0.17 g/l -272.2 -268.9 7440-59-7 1895 Ramsay & Cleve
3 Lithium Li Alkali Metals Solid 6.941(2) 0.53 180.5 1317 7439-93-2 1817 Arfwedson
4 Beryllium Be Alkaline Earth Metals Solid 9.012182(3) 1.85 1278 2970 7440-41-7 1797 Vauquelin
5 Boron B Metalloids Solid 10.811(7) 2.46 2300 2550 7440-42-8 1808 Davy & Gay-Lussac
6 Carbon C Nonmetals Solid 12.0107(8) 3.51 3550 4827 7440-44-0 Prehistoric Unknown
7 Nitrogen N Nonmetals Gas 14.0067(2) 1.17 g/l -209.9 -195.8 77-37-9 1772 Rutherford
8 Oxygen O Nonmetals,
Chalcogens
Gas 15.9994(3) 1.33 g/l -218.4 -182.9 7782-44-7 1774 Priestly & Scheele
9 Flourine F Halogens Gas 18.9984032(5) 1.58 g/l -219.6 -188.1 7782-41-4 1886 Moissan
10 Neon Ne Noble Gases Gas 20.1797(6) 0.84 g/l -248.7 -246.1 7440-01-9 1898 Ramsay and Travers
11 Sodium Na Alkali Metals Solid 22.98976928(2) 0.97 97.8 892 7440-23-5 1807 Davy
12 Magnesium Mg Alkaline Earth Metals Solid 24.3050(6) 1.74 648.8 1107 7439-95-4 1755 Black
13 Aluminium Al Poor Metals Solid 26.9815386(8) 2.7 660.5 2467 7429-90-5 1825 Oersted
14 Silicon Si Metalloids Solid 28.0855(3) 2.33 1410 2355 7440-21-3 1824 Berzelius
15 Phosphorus P Nonmetals Solid 30.973762(2) 1.82 44 (P4) 280 (P4) 7723-14-0 1669 Brand
16 Sulfur S Nonmetals Solid 32.065(5) 2.06 113 444.7 7704-34-9 Prehistoric Unknown
17 Chlorine Cl Halogens Gas 35.453(2) 2.95 g/l -34.6 -101 7782-50-5 1774 Scheele
18 Argon Ar Noble Gases Gas 39.948(1) 1.66 g/l -189.4 185.9 7440-37-1 1894 Ramsay & Rayleigh
19 Potassium K Alkali Metals Solid 39.0983(1) 0.86 63.7 774 7440-09-7 1807 Davy
20 Calcium Ca Alkaline Earth Metal Solid 40.078(4) 1.54 839 1487 7440-70-2 1808 Davy
21 Scandium Sc Transition Metals Solid 44.955912(6) 2.99 1539 2832 7440-20-2 1879 Nilson
22 Titanium Ti Transition Metals Solid 47.867(1) 4.51 1660 3260 7440-32-6 1791 Gregor & Klaproth
23 Vanadium V Transition Metals Solid 50.9415(1) 6.09 1890 3380 7440-62-2 1801 del Rio
24 Chromium Cr Transition Metals Solid 51.9961(6) 7.14 1857 2428 7440-47-3 1797 Vauquelin
25 Manganese Mn Transition Metals Solid 54.938045(5) 7.44 1244 2097 7439-96-5 1774 Gahn
26 Iron Fe Transition Metals Solid 55.845(2) 7.87 1535 2750 7439-89-6 Prehistoric Unknown
27 Cobalt Co Transition Metals Solid 58.933195(5) 8.89 1495 2870 7440-48-4 1735 Brandt
28 Nickel Ni Transition Metals Solid 58.6934(2) 8.91 1453 2732 7440-02-0 1751 Cronstedt
29 Copper Cu Transition Metals Solid 63.546(3) 8.92 1083.5 2595 7440-50-8 Prehistoric Unknown
30 Zinc Zn Transition Metals Solid 65.409(4) 7.14 419.6 907 7440-66-6 Prehistoric Unknown
31 Gallium Ga Poor Metals Solid 69.723(1) 5.91 29.8 2403 7440-55-3 1875 Lecoq de Boisbaudran
32 Germanium Ge Metalloids Solid 72.64(1) 5.32 937.4 2830 7440-56-4 1886 Winkler
33 Arsenic As Metalloids Solid 74.92160(2) 5.72 613 613
sublimation
7440-38-2 ca. 1250 Albertus Magnus
34 Selenium Se Nonmetals Solid 78.96(3) 4.82 217 685 7782-49-2 1817 Berzelius
35 Bromine Br Halogens Liquid 79.904(1) 3.14 -7.3 58.8 7726-95-6 1826 Balard
36 Krypton Kr Noble Gases Gas 83.798(2) 3.48 g/l -156.6 -152.3 7439-90-9 1898 Ramsay & Travers
37 Rubidium Rb Alkali Metals Solid 85.4678(3) 1.53 39 688 7440-17-7 1861 Bunsen & Kirchhoff
38 Strontium Sr Alkaline Earth Metals Solid 87.62(1) 2.63 769 1384 7440-24-6 1790 Crawford
39 Yttrium Y Transition Metals Solid 88.90585(2) 4.47 1523 3337 7440-65-5 1794 Gadolin
40 Zirconium Zr Transition Metals Solid 91.224(") 6.51 1852 4377 7440-67-7 1789 Klaproth
41 Niobium Nb Transition Metals Solid 92.90638(2) 8.58 2468 4927 7440-03-1 1801 Hatchett
42 Molybdenum Mo Transition Metals Solid 95.94(2) 10.28 2617 5560 7439-98-7 1778 Scheele
43 Technetium Tc Transition Metals Solid [98.9063] 11.49 2172 5030 7440-26-8 1937 Perrier & Segrè
44 Ruthenium Ru Transition Metals Solid 101.07(2) 12.45 2310 3900 7440-18-8 1844 Klaus
45 Rhodium Rh Transition Metals Solid 102.90550(2) 12.41 1966 3727 7440-16-6 1803 Wollaston
46 Palladium Pd Transition Metals Solid 106.42(1) 12.02 1552 3140 7440-05-3 1803 Wollaston
47 Silver Ag Transition Metals Solid 107.8682(2) 10.49 961.9 2212 7440-22-4 Prehsitoric Unknown
48 Cadmium Cd Transition Metals Solid 112.411(8) 8.64 321 765 7440-43-9 1817 Strohmeyer & Hermann
49 Indium In Poor Metals Solid 114.818(3) 7.31 156.2 2080 7440-74-6 1863 Reich & Richter
50 Tin Sn Poor Metals Solid 118.7107(7) 7.29 232 2270 7440-31-5 Prehistoric Unknown
51 Antimony Sb Metalloids Solid 121.760(1) 6.69 630.7 1750 7440-36-0 Prehistorc Unknown
52 Tellurium Te Metalloids Solid 127.60(3) 6.25 449.6 990 13494-80-9 1782 von Reichenstein
53 Iodine I Halogens Solid 126.90447(3) 4.94 113.5 184.4 7553-56-2 1811 Courtois
54 Xenon Xe Noble Gases Gas 131.293(6) 4.49 g/l -111.9 -107 7440-63-3 1898 Ramsay & Travers
55 Caesium Cs Alkali Metals Solid 132.9054519(2) 1.9 28.4/td> 690 7440-46-2 1860 Kirchhoff & Bunsen
56 Barium Ba Alkaline Earth Metals Solid 137.317(7) 3.65 725 1640 7440-39-3 1808 Davy
57 Lanthanum La Lanthanoids Solid 138.90547(7) 6.16 920 3454 7439-91-0 1839 Mosander
58 Cerium Ce Lanthanoids Solid 140.116(1) 6.77 798 3257 7440-45-1 1803 von Hisinger & Berzelius
59 Praeseodymium Pr Lanthanoids Solid 140.90765(2) 6.48 931 3212 7440-10-0 1895 von Welsbach
60 Neodymium Nd Lanthanoids Solid 144.242(3) 7.00 1010 3127 7440-00-8 1895 von Welsbach
61 Promethium Pm Lanthaniods Solid [146.9151] 7.22 1080 2730 7440-12-2 1945 Marinsky & Glendenin
62 Samarium Sm Lanthanoids Solid 150.36(2) 7.54 1072 1778 7440-19-9 1879 Lecoq de Boisbaudran
63 Europium Eu Lanthanoids Solid 151.964(1) 5.25 822 1597 7440-53-1 1901 Demarçay
64 Gadolinium Gd Lanthanoids Solid 157.25(3) 7.89 1311 3233 7440-54-2 1880 de Marignac
65 Terbium Tb Lanthanoids Solid 159.92535(2) 8.25 1360 3041 7440-27-9 1843 Mosander
66 Dysprosium Dy Lanthanoids Solid 162.500(1) 8.56 1409 2335 7429-91-6 1886 Lecoq de Boisbaudran
67 Holmium Ho Lanthanoids Solid 164.93032(2) 8.78 1470 2720 7440-60-0 1878 Soret
68 Erbium Er Lanthanoids Solid 167.259(3) 9.05 1522 2510 7440-52-0 1842 Mosander
69 Thulium Tm Lanthanoids Solid 168.93421(2) 9.32 1545 1727 7440-30-4 1879 Cleve
70 Ytterbium Yb Lanthanoids Solid 173.04(3) 6.97 824 1193 7440-64-4 1878 de Marignac
71 Lutetium Lu Lanthanoids Solid 174.967(1) 9.84 1656 3315 7439-94-3 1907 Urbain
72 Hafnium Hf Transition Metal Solid 178.49(2) 13.31 2150 5400 7440-58-6 1923 Coster & Hevesy
73 Tantalum Ta Transition Metals Solid 180.9479(1) 16.68 2996 5425 7440-25-7 1802 Ekeberg
74 Tungsten W Transition Metals Solid 183.84(1) 19.26 3407 5927 7440-33-7 1783 Elhuyar
75 Rhenium Re Transition Metals Solid 186.207(1) 21.03 3180 5627 7440-15-5 1925 Noddack, Tacke & Berg
76 Osmium Os Transition Metals Solid 190.23(3) 22.61 3045 5027 7440-04-2 1803 Tennant
77 Iridium Ir Transition Metals Solid 192.217(3) 22.65 2410 4130 7439-88-5 1803 Tennant
78 Platinum Pt Transition Metals Solid 195.084(9) 21.45 1772 3827 7440-06-4 1557 Scaliger
79 Gold Au Transition Metals Solid 196.966569(4) 19.32 1064.4 2940 7440-57-5 Prehistoric Unknown
80 Mercury Hg Transition Metals Liquid 200.59(2) 13.55 -38.9 356.6 7439-97-6 Prehistoric Unknown
81 Thallium Tl Poor Metals Solid 204.3833(2) 11.85 303.6 1457 7440-28-0 1861 Crookes
82 Lead Pb Poor Metals Solid 207.12(1) 11.34 327.5 1740 7439-92-1 Prehistoric Unknown
83 Bismuth Bi Poor Metals Solid 208.98040(1) 9.80 271.4 1560 7440-69-9 1540 Geoffroy
84 Polonium Po Metalloids Solid [2089824] 9.20 254 962 7440-08-6 1898 Marie & Pierre Curie
85 Astatine At Halogens Solid [209.987]   302 337 7440-68-8 1940 Corson & MacKenzie
86 Radon Rn Noble Gases Gas [122.0176] 9.23 g/l -71 -61.8 10043-92-2 1900 Dorn
87 Francium Fr Alkali Metals Solid [223.0197]   27 677 7440-73-5 1939 Perey
88 Radium Ra Alkaline Earth Metals Solid [226.0254 5.5 700 1140 7440-14-4 1898 Marie & Pierre Curie
89 Actinium Ac Actinoids Solid [227.0278 10.07 1047 3197 7440-34-8 1899 Debierne
90 Thorium Th Actinoids Solid 232.03806(2) 11.72 1750 4787 7440-29-1 1829 Berzelius
91 Protactinium Pa Actinoids Solid 231.03588(2) 15.37 1554 4030 7440-13-3 1917 Soddy, Cranston & Hahn
92 Uranium U Actinoids Solid 238.02891(3) 18.97 1132.4 3818 7440-61-1 1789 Klaproth
93 Neptunium Np Actinoids Solid [237.0482] 20.48 640 3902 7439-99-8 1940 McMillan & Abelson
94 Plutonium Pu Actinoids Solid [244.0642] 19.74 640 3327 7440-07-5 1940 Seaborg
95 Americium Am Actinoids Solid [243.0614 13.67 994 2607 7440-35-9 1944 Seaborg
96 Curium Cm Actinoids Solid [247.0703] 13.51 1340   7440-51-9 1944 Seaborg
97 Berkelium Bk Actinoids Solid [247.0703 13.25 986   7440-40-6 1949 Seaborg
98 Californium Cf Actinoids Solid [251.0796] 15.1 900   7440-71-3 1950 Seaborg
99 Einsteinium Es Actinoids Solid [252.0829]   860   7429-92-7 1952 Seaborg
100 Fermium Fm Actinoids Solid [257.0951]       7440-72-4 1952 Seaborg
101 Mendelevium Md Actinoids Solid [258.0986       7440-11-1 1955 Seaborg
102 Nobelium No Actinoids Solid [259.1009       10028-14-5 1958 Seaborg
103 Lawrencium Lr Actinoids Solid
(presumed)
[260.1053]       22537-19-5 1961 Ghiorso
104 Rutherfordium Rf Transition Metals Solid
(presumed)
[261.1087]       53850-36-5 1964/69 Flerov
105 Dubnium Db Transition Metals Solid
(presumed)
[262.1138]       53850-35-4 1967/70 Flerov
106 Seaborgium Sg Transition Metals Solid
(presumed)
[263.1182]       54038-81-2 1974 Flerov
107 Bohrium Bh Transition Metals Solid
(presumed)
[262.1229]       54037-14-8 1976 Oganessian
108 Hassium Hs Transition Metals Solid
(presumed)
[265]       54037.--57-9 1984 GSI(*)
109 Meitnerium Mt Transition Metals Solid
(presumed)
[266]       54038-01-6 1982 GSI
110 Darmstadtium Ds Transition Metals Solid
(presumed)
[269]       54083-77-1 1994 GSI
111 Roentgenium Rg Transition Metals Solid
(presumed)
[272]       54386-24-2 1994 GSI
112 Ununbium Uub Transition Metals Probably
Liquid
or Gas
[285]       54084-26-3 1996 GSI
113 Ununtrium Uut Poor Metals
(presumed)
Solid
(presumed)
[284]       54084-70-7 2004 JINR(*), LLNL(*)
114 Ununquadium Uuq Poor Metals
(presumed)
Solid
(presumed)
[289]       54085-16-4 1999 JINR
115 Ununpentium Uup Poor Metals
(presumed)
Solid
(presumed)
[288]       54085-64-2 2004 JINR, LLNL
116 Ununhexium Uuh Poor Metals
(presumed)
Solid
(presumed)
[292]       54100-71-9 1999 LBNL(*)
117 Ununseptium Uus Halogens
(presumed)
Solid
(presumed)
        87658-56-8 Undiscovered  
118 Ununoctium Uuo Noble Gases Gas
(presumed)
        54144-19-3 Undiscovered  
 
Notes (*)

CAS = Chemical Abstracts Service.
GSI = Gesellschaft für Schwerionenforschung (Society for Heavy Ion Research), Wixhausen, Darmstadt, Germany.
JINR = Joint Institute for Nuclear Research, Dubna, Moscow Oblast, Russia.
LLNL = Lawrence Livermore National Laboratory, Livermore, California, USA.
LBNL = Lawrence Berkeley National Laboratory, Berkeley, California, USA.
[atomic mass No.] = mass number of the longest-lived isotope of the element or characteristic isotopic composition.
 
Wikipedia - Periodic table