Question

hs chemistry unit 1 review guide
lesson 3: how does heat move between the blocks and ice?
vocabulary
review the following vocabulary words from our lesson.
kinetic energy
law of conservation of energy
macroscopic
gas
temperature
microscopic
solid
liquid
scales
particle - level
skill practice & self reflection
use the practice problems and self reflection to review each of the skills from the lesson.
skill 1:
explain how the kinetic energy of particles changes as a substance undergoes phase changes.
practice: fill in the blanks to make true statements using the words increase or decrease.

1. as gas becomes a liquid, the kinetic energy ---------
2. when kinetic energy ----------------- a solid will melt into a liquid.
3. in order for a substance to freeze from a liquid to a solid the kinetic energy must ------------------.
4. liquids becoming gas requires ------------------ kinetic energy.
5. use the statements that you completed above to describe the law of conservation of energy and how it relates to kinetic energy.

self reflection:
□ i can explain how the kinetic energy of particles changes as a substance undergoes phase changes.
additional
notes/evidence:

Explanation:

Step1: Understand phase - change and kinetic energy

When a gas becomes a liquid (condensation), the particles slow down. Kinetic energy is related to the motion of particles. Slower - moving particles have lower kinetic energy. So, as gas becomes a liquid, the kinetic energy decreases.

Step2: Analyze melting process

For a solid to melt into a liquid (melting), the particles need to move more freely. This requires an increase in kinetic energy. So, when kinetic energy increases, a solid will melt into a liquid.

Step3: Consider freezing process

When a substance freezes from a liquid to a solid (freezing), the particles become more ordered and move less. This means a decrease in kinetic energy. So, in order for a substance to freeze from a liquid to a solid the kinetic energy must decrease.

Step4: Examine vaporization

For liquids to become gas (vaporization), the particles need to gain enough energy to escape the liquid phase. This requires an increase in kinetic energy. So, liquids becoming gas requires increase kinetic energy.

Answer:

1. decreases
2. increases
3. decreases
4. increase