The amount of energy required to change one gram of a liquid substance into a gas is called its:

1. Water is noted for requiring an unusually large amount of energy to vaporize, which affects how living systems use sweating for cooling. 2. The text defines the term directly: "Water also has a high heat of vaporization, the amount of energy required to change one gram of a liquid substance to a" gas. 3. Specific heat instead concerns raising temperature (not changing phase), boiling point is a temperature value, and latent heat of fusion applies to melting/freezing, not vaporization. 4. So the energy needed to vaporize one gram of liquid is called the heat of vaporization. _Source: OpenStax Biology Ch 2 "The Chemical Foundation of Life", p.48 §2.2 | Water_