Why does air in a room rise when it gains thermal energy from a heater? (1 point)

Question

Responses

Its molecules move around more slowly, so there is more space between them, making it less dense than the air above it.
Its molecules move around more slowly, so there is more space between them, making it less dense than the air above it.

Its molecules move around more quickly, so there is more space between them, making it less dense than the air above it.
Its molecules move around more quickly, so there is more space between them, making it less dense than the air above it.

Its molecules move around more quickly, so there is more space between them, reducing its mass.
Its molecules move around more quickly, so there is more space between them, reducing its mass.

Warm air always rises.

Answer 1

The correct response is:

Its molecules move around more quickly, so there is more space between them, making it less dense than the air above it.

When air gains thermal energy from a heater, its molecules become more energetic and move around more rapidly. This increased motion causes the molecules to spread out, resulting in a decrease in density. Since warm air is less dense than cooler air, it rises.