“Properties of Matter” study guide
Complete A-F WITH THE PROPER PHASE CHANGE.
IV. Short Answer Questions: Answer these questions to the best of your ability. (10pts each).
32. What is the difference between endothermic changes and exothermic changes? Which phase changes are endothermic and which are exothermic?
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1. This is the phase change when a gas turns into a solid.
2. This states that all particles of matter are in constant motion.
3. Caused by the collisions of air particles and the walls of a container.
4. The phase change that occurs when a solid gains enough energy that its molecules move from their fixed positions.
5. The phase change that occurs when a solid turns into a gas.
6. The phase change when a liquid looses enough energy that molecules move into fixed positions.
7. Boiling and evaporation are two types of this phase change.
8. When a substance gains enough energy that its molecules overcome the attraction of neighboring molecules this occurs.
9. The phase change in which a substance changes from a gas or vapor to a liquid.
10. Vaporization that occurs in temperatures below the boiling point.
Which graph correctly shows the effect of heat energy on the motion of molecules of matter?
*represents the relative distance between the particles (one example is correct)
Which diagram best represents molecules of matter in each phase?
The chart below shows temperature readings recorded every minute while a substance was being heated at a constant rate. The material was a solid before heating and a hot liquid after 7 minutes of heating.
0 / 25
1 / 34
2 / 50
3 / 50
4 / 50
5 / 53
6 / 58
7 / 65
Based on the data, at what temperature did a phase change take place?
After reading the following paragraphs, answer the question below.
Instant cold packs are popular with coaches and parents for treating minor bumps and bruises. The instant cold packs are not pre-cooled—you just squeeze the cold pack and its starts to get cold. Many cold packs work by mixing ammonium nitrate salt with water.
Cold packs also contain distilled water and when the inner linings are broken; the ammonium nitrate reacts to the water and causes a reaction. Water and ammonium nitrate are kept in separate compartments in the pack until the pack is needed. Then the chambers are broken and the ammonium nitrate dissolves in the water, absorbing heat and making the pack cool from room temperature to as cold as 0 degrees Celsius.
Is this reaction an endothermic or exothermic change? Give evidence to back up your answer.
USE S, L, OR G:
Solids, Liquids and Gasses:
11. Has a definite shape and volume.
12. Takes the shape of the container but not the size.
13. When things melt they become this.
14. When deposition occurs substances turn into this.
15. Slow molecule vibration.
16. Water takes this form above 100 degrees Celsius.
17. Does not have a definite size or shape.
18. Has a definite size but not a definite shape.
19. Takes this form when molecules loose enough energy and get stuck into fixed positions.
20. Takes the shape and size of any container.