Diagram of a box containing several dark circles, each marked 8. Throughout this assessment you will see diagrams like this one. Each box represents an object. The circles in the box represent all of the molecules that make up the object. The numbers in the circles represents the amount of energy those molecules have.

Question

Photograph of a geyser emitting a tall stream of water and steam.
audio
speed
1. In some places, hot water from underground can shoot up into the air through a hole in the ground. When this happens, the ground surrounding the water increases in temperature. What happens to the molecules in the ground when the temperature of the ground increases?

Responses

a
More heat molecules combine with the molecules in the ground.
More heat molecules combine with the molecules in the ground.

b
The energy of the molecules in the ground decreases.
The energy of the molecules in the ground decreases.

c
The energy of the molecules in the ground increases.
The energy of the molecules in the ground increases.

d
The cold energy of the molecules in the ground decreases.

Answer 1

The correct response is:

c
The energy of the molecules in the ground increases.

When the temperature of the ground increases due to hot water from underground, the energy of the molecules in the ground also increases. This is because temperature is a measure of the average kinetic energy of the molecules, and an increase in temperature corresponds to an increase in molecular motion and energy.