Convection is the way heat travels through liquids and gases. The molecules of liquids and gases are not tightly packed. There are spaces between the molecules. This means that the molecules can move from place to place. The molecules closest to the heat get hot first. They vibrate faster. They also move. They move away from the heat. Cooler molecules move in and take their place. The cooler molecules are heated. then they move away. Other molecules move in to take their place. This happens over and over again. Little by little, all the molecules in the gas or liquid are heated . The molecules that were first heated cool a bit. Then they move back toward the heat and are heated again. This happens over and over - heating, cooling, and then re-heating. The passing along of heat by moving molecules is called convection. Only gases and liquids are heated by convection.
The up-and-down movements of gases and liquids due to uneven heating are called convection currents. Convection currents are responsible for our weather. In addition, convection occurs deep within the earth helping to shape our earth.
We did the "Convection Snake" and the "Spot Drop" activity in class to help explore convection.