1. What does the temperature of a substance primarily indicate about its molecules?
- A. The chemical bonds between the molecules
- B. The average kinetic energy of the molecules
- C. The total number of molecules in the substance
- D. The size of the individual molecules
2. The transfer of thermal energy between two objects in direct contact is primarily driven by what specific molecular interaction?
- A. Chemical reactions
- B. Magnetic attraction
- C. Collisions
- D. Gravitational forces
3. What is the direct result of a collision between a fast-moving molecule from a warm substance and a slow-moving molecule from a cool substance?
- A. The slow molecule speeds up, and the fast molecule slows down.
- B. The fast molecule gains even more speed from the collision.
- C. Both molecules are destroyed in the interaction.
- D. The slow molecule transfers its 'coldness' to the fast molecule.
4. The energy associated with the motion of molecules, which is transferred during collisions between warm and cool objects, is known as what?
- A. Potential energy
- B. Kinetic energy
- C. Nuclear energy
- D. Chemical energy
5. When a hot object touches a cold object, how is energy transferred between them at the molecular level?
- A. The faster molecules of the warm object transfer kinetic energy to the slower molecules of the cool object through collisions.
- B. The molecules from the cold object physically move into the warm object to absorb energy.
- C. The 'cold' from the cool object flows into the warm object, slowing its molecules down.
- D. Both objects lose energy to the surrounding air, causing them to eventually reach the same temperature.
6. When a flashlight is left on, its battery eventually "dies." According to the Law of Conservation of Energy, what has happened to the energy that was stored in the battery?
- A. The energy has been destroyed by the chemical reactions inside the battery.
- B. The energy has been converted into light and heat.
- C. The energy has been used up and no longer exists in any form.
- D. The energy has been transferred back to the power grid that charged it.
7. A person eats an apple, then goes for a run. Which of the following describes the primary energy conversions that occur?
- A. Kinetic energy to chemical energy to thermal energy.
- B. Chemical energy to kinetic energy and thermal energy.
- C. Thermal energy to chemical energy to kinetic energy.
- D. Potential energy to kinetic energy to chemical energy.
8. A bouncing ball never returns to its original drop height. According to the Law of Conservation of Energy, why does this happen?
- A. The impact with the ground permanently destroys a small fraction of the ball's total energy.
- B. Energy is converted into sound and heat.
- C. The system is not closed, so energy leaks out into the surrounding atmosphere without changing form.
- D. Potential energy is converted to kinetic energy, but the reverse conversion is not possible.
9. Imagine a perfectly insulated, sealed room containing a running refrigerator. What will happen to the overall temperature of the room over time?
- A. It will decrease.
- B. It will stay the same.
- C. It will increase.
- D. It will fluctuate up and down.
10. If a battery supplies 50 joules of electrical energy to a simple circuit with a light bulb, what must be true about the energy transformation within the battery itself?
- A. The battery created 50 joules of new electrical energy.
- B. The battery converted 50 joules of chemical energy.
- C. More than 50 joules of chemical energy were destroyed.
- D. The battery absorbed 50 joules of heat from the air.