Q. Which among the following has the highest calorific value?
Answer: Hydrogen
Notes: Hydrogen has the highest calorific value as it releases about 150 kilojoules (kJ) of energy per gram. This is nearly three times the energy yield of methane. It is often utilized in its liquid state because of its exceptional energy efficiency, especially in space exploration. The calorific value of coal is significantly less, which is then followed by wood, whose calorific value stands at a low 17 kJ/g.