Heat can travel through a medium and also through a vacuum. There are three modes of heat transfer namely; conduction,radiation and convection. Convection and conduction require a material medium but radiation can take place in a vacuum. Conduction takes place in solids while convection takes place in fluids. Mechanism by which solids transfer heat are vibration of atoms and free electrons. Convection is the process by which heat is transferred through fluids. Its by the actual movement of the fluid called convection currents.

1.Name the three modes of heat transfer.

2.Distinguish between conducton and convection.