Which energy change occurs during boiling?
some heat energy of the substance is lost.
heat energy of the substance remains the same
most heat energy of the substance is lost.
heat energy is absorbed by the substance.

Heat energy is absorbed by the substance

Explanation: Boiling is an endothermic process in which water molecules absorbs heat energy to break bonds. During boiling the amount of heat absorbed is used to break chemical bonds of water having its temperature remains in constant. The absorption of heat energy increases the kinetic energy of molecules which allows them to escape into the gaseous phase.