11-7-16
Chapter 4 Review Answer Key
1)B
2)Solids have definite shapes and volumes. This is because their particles are so compact and arranged in regular patterns. On the other hand, liquids have definite volumes, but not definite shapes. This is because their particles are not in as structured an arrangement as liquids.
3)Evaporation is the change of state from a liquid to a gas. It occurs ONLY at the surface of a liquid. Boiling is also a change of state from a liquid to a gas. It occurs throughout the liquid.
4)Condensation is the change of state from a gas to a liquid. Sublimation is the change of state from a solid to a liquid.
5)B
6)A
7)B
8)D
9)Gases have the highest speed of molecular movement, then liquids, and finally solids.
10)100 degrees C
11)Liquid water’s molecules slide past each other, which allows it to flow and take the shape of a container. Ice cube’s molecules in contrast are in a tight, organized structure. They cannot move past each other.
12)The molecular formula of water is the same in each of the solid, liquid, and gas states. These states must be physical changes and not chemical changes.
13)The boiling point is 80 degrees C. The melting point is 20 degrees C.
14)The substance is melting.
15)Answers can vary…make sure to include the following trends:
- Particles lose energy
- Particles move slower
16)SKIP
17)Because the gas particles move quickly, they can move the glass tubes around as they travel up and out of the apparatus.
18)The water must be at 100 degrees C.
19)The water is heated by a water heater. It gets so hot that it vaporizes in the bathroom. This vapor eventually cools and condenses on the mirror.
20)Water has a stronger cohesive force between its molecules. One can tell this is true because of its higher boiling point at a given pressure.
21)No, this is not a change of state, because the reactants have a different chemical makeup than the products.
22)She could test the bubbles. If they contain water vapor, then the water is boiling.
23)The graph is linear. There must be a direct relationship between the surface area (cm2) and the volume evaporated in a given time.
*Note: If you have questions about the graph, come talk to me tomorrow morning before school.
24)Heat is given off by the water while it freezes. This increases the oranges’ temperature, so they don’t freeze.
Altered from:
Borgford, C. L. (2007). Holt California physical science. Orlando, FL: Holt, Rinehart and Winston.