Smart Facts On CONVECTION
Ten things you never knew about convection – share these fascinating facts with your KS3 science students.
- When a balloon is full of hot air, it lifts off the ground because the hot air inside it is less dense than the cold air outside it.
- Convection also takes place within the Sun. Vast amounts of hot gas rise up towards the surface of the Sun. They then become cooler and sink towards the centre of the Sun.
- The temperature at the bottom of the convection zone in the Sun is 200,000° C. The temperature at the surface is only about 5700° C, as it is being cooled by the creation of light.
- The bottom of the convection zone in the Sun is located at a depth of about 200,000 km
- Convection currents are responsible for the movement of tectonic plates on the Earth’s crust, the production of wind in the atmosphere, and the production of ocean currents.
- Forced convection occurs when a pump or other mechanism moves the heated fluid. This is used in some types of ovens and refrigerators.
- A convection cell is the circular pattern created by the rising of warmed fluid and the sinking of cooled fluid. Convective cells may be only a few millimetres across, or they may be larger than Earth itself.
- The energy that drives convection in the Earth’s mantle is geothermal, rising up from Earth’s core as a result of radioactive decay.
- Convection stops people being poisoned by nasty gases! The Stack effect, or chimney effect, is the movement of air into and out of buildings, chimneys, flue gas stacks, or other containers by convection.
- A thermal column (or thermal) is a vertical section of rising air in the Earth’s atmosphere. This stops gliders from crashing by lifting them up!
By Mark Prince for Smart Learning