Question

What are convection currents?
It is when a cooled solid rises, heats up and then sinks again. Creating a cycle.
It is when a heated solid rises, cools down and then sinks again. Creating a cycle.
It is when a cooled liquid or gas rises, heats up and then sinks again. Creating a cycle.
It is when a heated liquid or gas rises, cools down and then sinks again. Creating a cycle.

Answer 1

energy in a liquid or gas move and take the place of particles with less heat energy. Heat energy is transferred from hot places to cooler places by convection. Liquids and gases expand when they are heated.