Heating Curves & Energy During Phase Change — Drills · Grade 8 Science
Chapter: Phases of MatterWhat these drills covers
By the end of Heating Curves & Energy During Phase Change you should be able to:
- I can interpret a heating graph’s axes, rising intervals and phase-change plateau.
- I can account for energy input during melting and distinguish temperature from a complete energy account.
4 questions, written answer, each with a worked explanation.
Vocabulary used: heating curve, phase, plateau, latent heat, coexistence, model, evidence, system boundary, assumption.
Problem 1
Answer and explanation
Temperature at recorded times. A constant-rate assumption connects time with energy input; the graph does not directly measure every energy pathway.
Temperature at recorded times. A constant-rate assumption connects time with energy input; the graph does not directly measure every energy pathway.
Response criteria
- Use the supplied conditions and relevant evidence.
- Explain the scientific mechanism or calculation.
- State a meaningful limitation or testable next step.
Problem 2
Answer and explanation
No. They vibrate in the solid. Warming changes their motion; melting later changes the larger arrangement and freedom to move.
No. They vibrate in the solid. Warming changes their motion; melting later changes the larger arrangement and freedom to move.
Response criteria
- Use the supplied conditions and relevant evidence.
- Explain the scientific mechanism or calculation.
- State a meaningful limitation or testable next step.
Problem 3
Answer and explanation
A decreasing solid fraction and increasing liquid fraction while energy is supplied. Temperature alone is insufficient to describe the complete state.
A decreasing solid fraction and increasing liquid fraction while energy is supplied. Temperature alone is insufficient to describe the complete state.
Response criteria
- Use the supplied conditions and relevant evidence.
- Explain the scientific mechanism or calculation.
- State a meaningful limitation or testable next step.
Problem 4
Answer and explanation
No. Pure ice, a solid–liquid mixture or liquid at that temperature may be possible under the stated conditions; additional state evidence is needed.
No. Pure ice, a solid–liquid mixture or liquid at that temperature may be possible under the stated conditions; additional state evidence is needed.
Response criteria
- Use the supplied conditions and relevant evidence.
- Explain the scientific mechanism or calculation.
- State a meaningful limitation or testable next step.