rjara rjara 23-04-2020 Chemistry contestada Which of the following are decomposition reactions? * 1. CH4 (g) + O2(g) → CO2 (g) + H20 (1) 2. Cao (s) + CO2(g) → CaCO3 (s) 3. Mg (s) + O2 (g) – Mgo (s) 4. POCO3 (s) – Pbo (s) + CO> (9)