Fill in the Blanks Convection Online version How does heat transfer through liquids and gasses? by Aaron Stinson 1 current expansion contraction gasses climate convection liquids density The transfer of thermal energy by the movement of particles from one part of a material to another is called , convection occurs in fluids and . Convection occurs , in part , because of difference in due to thermal and thermal in different parts of the material Te movement of fluids up and down in a cycle because of convection is called a convection , these currents cause patterns in Earth .