Which statement about convection in fluids is correct?
Convection currents can only occur in liquids.
When a fluid is heated, it expands, becomes less dense, and rises.
When a fluid is cooled, it contracts, becomes less dense, and sinks.
Convection currents occur in solids when particles vibrate about fixed positions.
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.