1. What does the temperature of a substance directly measure?
- A. The total number of particles in the substance
- B. The average kinetic energy of the particles in the substance
- C. The specific speed of a single, individual particle
- D. The potential energy stored within the chemical bonds of the particles
2. A student has two identical glasses of water. Glass A is at 80°C and Glass B is at 20°C. How does the motion of water molecules in Glass A compare to Glass B?
- A. The molecules in Glass A are, on average, moving more slowly than in Glass B.
- B. The molecules in both glasses are moving at the exact same average speed.
- C. The molecules in Glass A are, on average, moving more rapidly than in Glass B.
- D. The molecules in Glass A have stopped moving, while the molecules in Glass B are moving slowly.
3. If you place a pot of cold water on a hot stove, what is happening to the water molecules as the water's temperature increases?
- A. Their average kinetic energy is increasing.
- B. Their average kinetic energy is decreasing.
- C. They are changing into a different type of molecule.
- D. They are getting larger in size.
4. The text describes temperature as a "speedometer for molecules." Why is this a fitting analogy?
- A. Because temperature indicates the exact direction each molecule is traveling.
- B. Because temperature provides a measure of the average speed of molecular motion.
- C. Because temperature only works for substances that are moving, like a car.
- D. Because a thermometer's needle looks and functions exactly like a car's speedometer.
5. An ice cube is taken out of a freezer and placed on a counter. As it absorbs energy from the room and begins to melt, what is happening to the average kinetic energy of its water molecules?
- A. It is increasing.
- B. It is decreasing.
- C. It remains exactly the same.
- D. It drops to zero.
6. When a substance is heated, what is the primary effect on the kinetic energy of its molecules?
- A. It is converted into potential energy, holding the molecules in place.
- B. It increases, causing the molecules to move faster.
- C. It decreases, causing the molecules to slow down.
- D. It remains unchanged, but the substance's density increases.
7. Which of the following best defines the process of 'heating' in a scientific context?
- A. The process of transferring energy into a substance.
- B. The process of an object becoming hotter to the touch.
- C. The creation of new energy within a system's molecules.
- D. The measurement of an object's temperature with a thermometer.
8. How does the average motion of molecules in a cup of hot soup compare to the average motion of molecules in a bowl of cold gazpacho?
- A. The molecules in the cold gazpacho move faster on average.
- B. The molecules in both soups move at the exact same average speed.
- C. The molecules in the hot soup move faster on average.
- D. The type of motion is different; molecules in hot soup vibrate while molecules in cold soup slide past each other.
9. When energy is transferred to a substance through heating, what form of energy do its individual molecules primarily gain?
- A. Chemical energy
- B. Nuclear energy
- C. Kinetic energy
- D. Potential energy
10. A scientist observes that the molecules in a sample of gas are beginning to move more slowly and are clumping closer together. What process is most likely occurring?
- A. The gas is undergoing a chemical reaction to form a new substance with slower molecules.
- B. The pressure on the gas is being significantly decreased, allowing it to spread out and slow down.
- C. The gas is being cooled, which involves the removal of energy from the system.
- D. The gas is being heated, which causes the molecules to expand and then slow down.