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. Like zinc, it prefers oxidation state +2 in most of its compounds and like mercury it shows a low melting point compared to transition metals.
Three reasons Cadmium stands out
- 1
A soft, toxic metal used in batteries and pigments.
- 2
Industrial pollution from this metal in Japan caused a painful bone-weakening disease known as "itai-itai" disease.
- 3
Its telluride compound is used in thin-film solar panels as an efficient light-absorbing material.
A useful metal with a toxic legacy
Cadmium’s corrosion resistance once encouraged widespread electroplating, pigments, and rechargeable batteries. The element accumulates in kidneys and can weaken bone, leading to tighter controls and recycling programs. Cadmium telluride solar cells remain an important modern use, sealed into thin semiconductor layers.