Question

Hypothesis: If a fixed amount of gas is heated, then the volume will
because
the heat will cause the molecules of gas to move

Answer 1

Completed hypothesis:
"If a fixed amount of gas is heated, then the volume will increase, because the heat will cause the molecules of gas to move faster and collide more often and more forcefully with the container walls, causing the gas to expand."

Clarification and brief explanation:
- This statement assumes the gas is allowed to expand (pressure is held roughly constant). Under that condition Charles's law applies: V ∝ T (temperature must be in kelvin).
- If the gas is confined in a rigid container so volume cannot change, heating instead increases the pressure.

Short experimental check:
- Keep amount of gas constant, measure initial volume and temperature, raise temperature while allowing the container to expand (e.g., a syringe with a loose piston) and record volume. You should see volume increase roughly proportionally to temperature (in kelvin).