 |
|
|
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 |
|  |