Cadmium

Cadmium
|Name: Cadium                                                       |Group in periodic table: 12                                         |
|Symbol: Cd                                                         |Group name: (none)                                                 |
|Atomic number: 48                                                   |Period in periodic table: 5                                         |
|Atomic weight: 112.411 (8) [see note g]                             |Block in periodic table: d-block                                   |
|Standard state: solid at 298 K                                     |Color: silvery grey metallic                                       |
|CAS Registry ID: 7440-43-9                                         |Classification: Metallic                                           |

      Cadmium is a minor metallic element, one of the naturally occurring components in the earth’s crust and waters, and present everywhere in our environment. It was first discovered in Germany in 1817 as a by-product of the zinc refining process. Its name is derived from the Latin word cadmia and the Greek word kadmeia that are ancient names for calamine or zinc oxide.
          Naturally-occurring cadmium-sulfide based pigments were used as early as 1850 because of their brilliant red, orange and yellow colors, and appeared prominently in the paintings of Vincent Van Gogh in the late 1800s. Germany was the first and only commercial producer of cadmium metal for industrial applications up until World War I. Thomas A. Edison in the United States and Waldemar Junger in Sweden developed the first nickel-cadmium batteries early in the 20th Century. However, the most significant early use of cadmium was as a sacrificial corrosion protection coating on iron and steel.
        Exposure to certain forms and concentrations of cadmium is known to produce toxic effects on humans. Long-term occupational exposure to cadmium at excess...