Which of the following represents an endothermic process?

The melting of ice represents an endothermic process because it involves the absorption of heat from the surroundings. In this process, ice molecules gain sufficient energy to overcome the hydrogen bonds holding them in their solid form, thereby transitioning into liquid water. This energy absorption results in a temperature decrease in the surroundings, demonstrating the endothermic nature of the reaction.

In contrast, processes like the condensation of steam and the combustion of gasoline are exothermic, where energy is released to the surroundings. The reaction of sodium with water also releases heat as sodium reacts and ignites. Therefore, melting ice clearly stands out as the only endothermic process among the choices given.