Calcium

Definition: Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. source: Wikipedia

ID

5540006

ID date

2 Nov 2006

Previous ID

3518711000001109

Name

Calcium