Question

2.2.2 quiz: thermal energy and matter
question 1 of 10
a bar of gold has a temperature of 31°c, and a bar of aluminum has a temperature of 27°c. which statement explains why the bar of aluminum has a lower temperature?

a. the gold bar has a higher density than that of the aluminum bar.

b. the particles that make up the aluminum bar are moving faster.

c. the particles that make up the aluminum bar are moving more slowly.

d. the aluminum bar has more thermal energy.

Explanation:

To solve this, we analyze each option:

• Option A: Density is unrelated to temperature differences here. So A is incorrect.
• Option B: Higher temperature means faster - moving particles. Since aluminum is at a lower temperature ($27^{\circ}C$ compared to gold's $31^{\circ}C$), its particles should move slower, not faster. So B is incorrect.
• Option C: Temperature is related to the average kinetic energy of particles. Lower temperature means particles have less kinetic energy and move more slowly. Aluminum has a lower temperature, so its particles move more slowly. This is correct.
• Option D: Thermal energy depends on mass, specific heat, and temperature. We don't know the mass or specific heat, but generally, a lower - temperature object (assuming same or similar mass and specific heat) has less thermal energy. So D is incorrect.

Answer:

C. The particles that make up the aluminum bar are moving more slowly.