Answer:
3). Chemical potential energy
1). lower in charcoal than in coal.
Explanation:
Chemical potential energy is defined as the energy that can be absorbed or stored in a substance's chemical bonds. It can be released when there is a change in the number of particles of the substance.
As per the question, coal releases more heat than charcoal because 'the chemical potential energy of charcoal is lower than the coal' and hence, the latter would release more heat on burning i.e. the energy that was absorbed in the chemical bonds of the substance. Hence, option 3 and 1 are the correct answers.