Question

Which is an endothermic process?


the process in which a substance loses heat energy



the process in which a substance loses kinetic energy



the process in which the molecular motion of a substance decreases



the process in which a substance gains energy

Answer 1

Answer: Option (d) is the correct answer.

Explanation:

Endothermic process is a process in which energy or heat is absorbed by reactant species.

For example, melting of ice cubes is an endothermic process as it is absorbing heat from the surrounding and gives a cooling effect.

Thus, we can conclude that the process in which a substance gains energy is an endothermic process.

Answer 2

Answer:

The process in which a substance gains energy.

Explanation:

In an endothermic process, a system absorbs energy from the surroundings, therefore increasing its internal energy.

Which is an endothermic process?

• the process in which a substance loses heat energy. NO. This is an exothermic process because energy is transferred from the system to the surroundings.
• the process in which a substance loses kinetic energy. NO. According to the Law of Conservation of Energy, the total energy of an isolated system remains constant, that is, it cannot be created nor destroyed, only transferred and transformed from one form to another. In this case, kinetic energy lost by the substance is gained by the surroundings, so it is an exothermic process.
• the process in which the molecular motion of a substance decreases. NO. This is connected to the previous option. If molecular motion decreases it is because kinetic energy is being lost and transferred to the environment, in an exothermic process.
• the process in which a substance gains energy. YES. This coincides with the definition of an endothermic process.