Answer: (a) Calcium
Calcium reacts with oxygen to give calcium oxide.
- The chemical formula of calcium oxide is CaO.
- The molecule is formed by the calcium cation Ca+2 and the oxygen anion O2-, which form an ionic bond.
- Calcium oxide appears as an odourless, white or gray-white solid in the form of hard lumps.
Calcium oxide combines with water to form calcium hydroxide as it reacts with it. Calcium oxide is soluble in water to give Calcium Hydroxide.
CaO + H2O → Ca(OH)2