Discovery date : 1817
Discovered by: Friedrich Stromeyer
Origin of the name: The name is derived from the Latin 'cadmia', the name for the mineral calmine.
Allotropes :
~>CADMIUM is a chemical element with symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury.
| FACT BOX | |||
| Group | 12 | Melting point | 321.069°C, 609.924°F, 594.219 K |
| Period | 5 | Boiling point | 767°C, 1413°F, 1040 K |
| Block | d | Density (g cm−3) | 8.69 |
| Atomic number | 48 | Relative atomic mass | 112.414 |
| State at 20°C | Solid | Key isotopes | 114Cd |
| Electron configuration | [Kr] 4d105s2 | CAS number | 7440-43-9 |
| ChemSpider ID | 22410 | ChemSpider is a free chemical structure database | |
In the early 1800s, the apothecaries of Hanover, Germany, made zinc oxide by heating a naturally occurring form of zinc carbonate called cadmia. Sometimes the product was discoloured instead of being pure white, and when Friedrich Stromeyer of Göttingen University looked into the problem he traced the discoloration to a component he could not identify, and which he deduced must be an unknown element. This he separated as its brown oxide and, by heating it with lampblack (carbon), he produced a sample of a blue-grey metal which he named cadmium after the name for the mineral. That was in 1817. Meanwhile two other Germans, Karl Meissner in Halle, and Karl Karsten in Berlin, were working on the same problem and announced their discovery of cadmium the following year.