Question

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

Warm air always rises.
Warm air always rises.

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.

Answer 1

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

Explanation: Heating increases the air molecules' kinetic energy, the air expands (lower density), and the cooler denser air above pushes the warmer air upward (buoyancy).