There are three modes of heat transmission.

• Radiation - is the transfer of heat where there is no contact and no intermediary substance or object, no mediu. An example of radiation is the sun heating the Earth. Every hot body radiates heat and will eventually cool when it runs out of fuel.

• Convection - movement of gas or liquid particles cause the transfer of heat. An example od conduction is when you boil a pot of water and hot water molecules rise to the top and heat the colder molecules there. The colder molecules also fall to the bottom. In this way heat is distributed throughout the pot of water until all of it reaches boiling.

• Conduction - when heat is transferred from one object or substance to another by direct contact. An example of conduction is the ironing of clothes. Heat is directly transferred from the iron the cloth.

A substance/object is a conductor of heat and has high heat conductivity if it allows heat to readily move through it. Or it is an insulator and has low heat conductivity if heat moves slowly through it. A cooking pan is an example of a conductor, and oven mitts are an example of insulators.