Which statement about convection is correct?
Convection occurs in fluids because, when heated, a fluid expands and becomes less dense.
Convection occurs in fluids because, when heated, a fluid contracts and becomes more dense.
Convection can only occur in gases.
Convection can occur in solids, liquids, and gases.
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.