1. Which statement best describes the primary characteristic of a gas that distinguishes it from a liquid?
- A. A gas has a fixed shape, while a liquid does not.
- B. A gas has a definite volume, while a liquid does not.
- C. A gas does not have a definite volume, while a liquid does.
- D. A gas is always visible, while a liquid is always colorless.
2. Based on the property of expansion, what can be inferred about the movement of gas molecules within a sealed container?
- A. The molecules are arranged in a fixed, orderly pattern.
- B. The molecules are in constant motion, causing them to spread out.
- C. The molecules slide past one another but remain in a defined volume.
- D. The molecules only vibrate in place and do not travel far.
3. Imagine 50 mL of a gas is carefully transferred from a 50 mL flask into a 2-liter (2000 mL) empty jug, which is then sealed. What will the volume of the gas be inside the jug?
- A. 50 mL
- B. 1950 mL
- C. 2000 mL
- D. The volume cannot be determined without knowing the temperature.
4. Which of the following everyday situations is the best example of a gas expanding to fill its container?
- A. An ice cube melting into water in a glass.
- B. Pouring sand from a bucket into a sandbox.
- C. Inflating a bicycle tire with an air pump.
- D. A sugar cube dissolving in a cup of hot tea.
5. A small amount of air is pumped into a large, empty, rigid metal tank which is then sealed. Which statement accurately describes the behavior of the air inside the tank?
- A. The air will form a small pocket at the bottom of the tank.
- B. The air molecules will spread out to occupy the entire volume of the tank.
- C. The air will remain concentrated near the valve where it was pumped in.
- D. The air will rise and form a thin layer at the very top of the tank.
6. What is a key characteristic of a solid object?
- A. It changes its shape to fit any container.
- B. It maintains its own rigid structure and shape.
- C. It can be poured easily from one place to another.
- D. It will spread out to cover the bottom of a surface.
7. A student pours juice from a carton into a tall glass. The juice now has the shape of the glass. This observation demonstrates that juice is a...
- A. solid.
- B. liquid.
- C. rock.
- D. fixed substance.
8. If you place a small, round pebble into a square box, the pebble remains small and round. What does this tell you about the pebble's state of matter?
- A. It is a liquid because it is small.
- B. It is a liquid because it is at the bottom of the box.
- C. It is a solid because it did not change its shape.
- D. It is a solid because the box is square.
9. Why does spilled milk spread out on the floor instead of staying in one drop?
- A. Because the floor is a solid.
- B. Because milk is a liquid that can flow.
- C. Because the milk is trying to evaporate.
- D. Because the floor is colder than the milk.
10. A scientist is trying to identify an unknown substance. The scientist observes that the substance holds its shape when placed on a table. This observation is the first clue that the substance is a...
- A. liquid.
- B. solid.
- C. container.
- D. fluid.