When a mixture of iron powder and sulphur powder is heated strongly to form iron sulphide, then heat energy is :(a) released(b) first absorbed and then released(c) absorbed(d) neither absorbed nor released

Correct Answer: (b) first absorbed and then released

Explanation: When a mixture of iron and sulphur is heated strongly, they first absorb the energy to get excited and forms a new compound iron sulphide (FeS) with the release of a huge amount of energy in the form of heat and light.