1. Those of them higher than hydrogen in the electrochemical series liberate hydrogen when treated with dilute acid.
Mg(s) + 2HCL(aq) → NgCL2(aq) + H2(g)
2. As reducing agent-metals are very good reducing agents.
2Zn(s) + CO2(g) → 2ZnO(s) + C(s)
3. Most metals react with oxygen to form basic oxides
2Mg(s) + O2(g) → 2MgO(s)