what happens to the positions motion and speed of the molecules in a solid as it is heated
1 Adding heat energy increases the motion of molecules. 2  Removing heat energy, or cooling, decreases the motion of molecules. 3  If heat is added to a solid, the molecules can move fast enough to change from a solid to a liquid.
1 Removing heat energy, or cooling, decreases the motion of molecules. 2  If heat is added to a solid, the molecules can move fast enough to change from a solid to a liquid. ( 3 Melting). 4  If heat is added to a liquid, the molecules can move fast enough to change from a liquid to a gas.