Explain properties and state changes using particles, and interpret a heating curve.
| English | Chinese |
|---|---|
| arrangement | 排列 |
| separation | 间距 |
| vibration | 振动 |
| kinetic energy | 动能 |
| heating curve | 升温曲线 |
| attraction | 吸引力 |
Try each question before opening its hint or answer. Use paper for calculations and diagrams.
A pure solid is melting while being heated. Why can its temperature stay constant?
Is the added energy increasing particle speed or overcoming attractions?
The energy is used to overcome attractions between particles during the change of state, rather than increasing their average kinetic energy.
Describe one difference in particle arrangement and one difference in motion between a solid and a gas.
Use fixed positions, spacing and random motion.
Solid particles are close together and vibrate about fixed positions. Gas particles are far apart and move rapidly and randomly throughout the container.
A student says that particles themselves become larger when a substance is heated. Correct this model.
Does heating normally change particle size or motion and separation?
The particles do not become larger. Heating generally increases their average kinetic energy; increased separation can cause expansion.
For more written practice, use Lesson 3 in your worksheet. Your teacher will discuss those answers in class.
Heat a solid in the simulation. Observe how particle arrangement and movement change. Use the simulation qualitatively, rather than as a precise heating curve.
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