The amount of heat needed to change a given amount of liquid to a gas without a change in temperature is its HEAT OF VAPORIZATION , sometimes referred to as latent ( hidden ) heat.
(heat; needed; to change a given amount of liquid to a gas without a change in temperature) (The amount of heat; is; its HEAT OF VAPORIZATION)
heat The amount of heat
needed is
to change a given amount of liquid to a gas without a change in temperature
its HEAT OF VAPORIZATION