Which of the following compounds undergoes/undergo thermal decomposition?

Thermal decomposition refers to a chemical reaction where a substance breaks down into simpler substances upon heating. Metal oxides vary in thermal stability based on the reactivity of the metal. Oxides of highly reactive metals like magnesium and zinc are extremely stable and do not decompose easily by heat alone [1]. Magnesium oxide (MgO) and zinc oxide (ZnO) have very high melting points and require significant energy or reducing agents like carbon for reduction [1][2]. In contrast, oxides of metals low in the reactivity series, such as silver and mercury, are thermally unstable. Silver oxide (Ag2O) decomposes into silver metal and oxygen gas at relatively low temperatures, typically above 250°C. Therefore, among the given options, only silver oxide undergoes thermal decomposition under standard laboratory heating conditions.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 3: Metals and Non-metals > ZnCO (s) ZnO(s) + CO (g) 3 2 → Heat > p. 51
2. [2] Science , class X (NCERT 2025 ed.) > Chapter 3: Metals and Non-metals > QUESTIONS > p. 55