7.1 Heat transfer by Convection and Radiation

This process happend inside the earth as well. Heat from the earths core is transferred the surface, this is what allows tectonic plates to move. This is an example of convection

Name a real life example of convection

Energy first transfers from the hot pan to the water molecules touching the pan. The water molecules then move faster taking up more space as they expand. The heated water molecules near the bottom of the pan will then rise to the top, while cooler water molecules take their place. Heated water molecules take thermal energy with them as they move.

What happens when a saucepan containing water is heated

When the sun radiates energy it travels through the atmosphere(medium). Some of this energy is absorbed by the ground while other parts of the ground may reflect it. It may be also be reflected and absorbed by clouds.

What is an example of radiation

Convection is the liquids and gases transfer thermal energy. Convection currents carry the thermal energy. A convection current is a movement withing liquids and gases.

What is convection

Radiation is a method of heat transfer that isn't reliant on the heat source and the object being heated making direct contact, unlike conduction and convection. Radiation does not require a medium to move through, it is able to move through empty space.

What is radiation

We heat liquids from below because almost all energy transfer in liquids and gases takes place by convection. When we heat liquids from below the water molecules absorb the heat and rise to the surface of the water taking the thermal energy with them. Cooler water molecules will then take their place and the pattern continues, until the entire container is hot. This situation of course encourages convection

Why do we heat liquid from below

When this is done only the surface of the water is heated. Hot water molecules rise to the surface, meaning that cooler water molecules will never be heated as they are underneath the already heated molecules. This situation discourages the use convection to heat the water.

Why don't we heat liquids from below