A heater is switched on at floor-level in a cold room. A student notices that the air near the ceiling becomes warm while the air near the floor remains colder. This is due to convection.
Which statement is correct?
Warm air is less dense than cold air so it rises to the ceiling of the room.
Warm air is more dense than cold air so it rises to the ceiling of the room.
The molecules in cold air have more kinetic energy than the molecules in warm air so they sink to the floor of the room faster.
The molecules in warm air are closer together than the molecules in cold air so they rise to the ceiling of the room.
73 exam-style questions on CIE IGCSE Physics 2.3.2 Convection. Each one has a worked solution and a mark scheme showing where the marks go.