Question

phase changes and chemical reactions worksheet
part 1: defining the basics refer to your notes from slide 3 and slide 9 to answer these questions.

1. true or false: mass changes if you take an object to the moon. (circle one)
2. what is the main difference between a phase change and a chemical reaction? (hint: see slide 10)
3. why is rusting considered a chemical reaction rather than just a phase change?

part 2: particle movement match the state of matter to the correct description of its particles. (refer to slides 5 - 7)

1. solid:
2. liquid:
3. gas:

a. particles move rapidly and freely.
b. particles are packed tightly and vibrate in place.
c. particles are close but can slide past one another.

Explanation:

1. Mass is an intrinsic property, not affected by location/gravity.
2. Phase changes only alter physical state; chemical reactions form new substances.
3. Rusting creates a new substance (iron oxide) from iron.
4. Solids have tightly packed, vibrating particles.
5. Liquids have close particles that slide past each other.
6. Gases have fast, freely moving particles.

Answer:

1. False
2. A phase change is a physical change that only alters the state of matter without forming new substances, while a chemical reaction breaks and forms chemical bonds to create entirely new substances with different properties.
3. Rusting is a chemical reaction because it converts iron (Fe) into a new substance, iron oxide (rust, $\text{Fe}_2\text{O}_3$), through a chemical bond rearrangement, rather than just changing the physical state of iron.
4. B. Particles are packed tightly and vibrate in place.
5. C. Particles are close but can slide past one another.
6. A. Particles move rapidly and freely.