🔍 Key Concepts

• Section 2 on the diagram corresponds to what is happening to the water’s temperature and state (solid, liquid, or vapor). • Difference between latent heat (heat added with no temperature change during a phase change) and sensible heat (heat that changes temperature). • Meaning of latent heat of fusion (melting/freezing of ice–water at 32°F) versus fission (a nuclear process, not a normal water phase change).

💭 Think About

• In section 2, is the water changing phase or just getting warmer in the same phase? • At what temperature and state does latent heat of fusion act in this diagram, and which labeled region on the chart shows that behavior? • Does the term fission normally apply to heating/cooling water, or is it related to something entirely different in physics?

✅ Before You Answer

• Identify whether temperature is changing or staying constant in section 2. • Identify whether the water is ice, liquid water, or steam in section 2. • Match the behavior in section 2 to the correct type of heat: latent heat (during phase change at constant temperature) or sensible heat (temperature change without phase change) before choosing your answer.