Choose the answer that takes place when a liquid absorbs heat energy without increasing its temperature.

a.) the pressure increases
b.) it vaporizes
c.) it solidifies
d.) the volume decreases

When a liquid absorbs heat energy without increasing its temperature is because it is using the absorbed heat for the change of phase from liquid to vapor. This is call vaporization. Vaporization requires energy because the molecules have to overcome the interaction that keeps them close to their neighbors in the liquid.So, the answer is the option B.) it vaporizes.