3. What temperature and density changes occur in a fluid or gas material that cause convection to occur?

There is an increase in density and a corresponding increase in the temperature of the fluid

Explanation:

The temperature and density changes occur in a fluid or gas material that cause convection to occur include increase in density and a corresponding increase in the temperature of the fluid.

This is because convection involves the movement of fluids from a hotter area to a colder area and hot fluids usually have a lower density.