Which event is endothermic? a)the burning of a matchb)the change of water vapor to a liquidc)the combustion of propane gasd)the melting of ice

Option (d) is the correct answer.

Explanation:

When heat is absorbed by reactant molecules then the reaction is known as endothermic reaction. In this reaction energy of products is more than the energy of reactant molecules.

For example, when ice is kept at room temperature then it absorbs heat from the surrounding and it start to melt. Therefore, solid state of water (ice) changes into liquid state of water.

Whereas when heat released by reactant molecules then the reaction is known as exothermic reaction. In this reaction energy of products is less that the energy of reactants.

For example, burning of a match is an exothermic reaction.

Thus, we can conclude that out of the given options event of melting of ice is endothermic.