Detailed Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Q: Passage: The temperature at which a substance boils and changes to a gas is called its boiling point. Boiling point is a physical property of matter. The boiling point of pure water is 100C. Other substances may have higher or lower boiling points. Several examples are listed in the Table below . Pure water is included in the table for comparison. Answer: boiling point
A:
What is the term for when a substance boils and changes to gas?