Asmall solid piece of wax is in a dish as shown below. the dish is briefly placed under a hot lamp.
imagine you could track one particle of wax. as the wax is heated (but not heated enough to melt), how would a particle in the wax move?

answers are in the pic

option C The particle would vibrate faster but stay in the same location.

The solid state of the matter is featured by the position of the atoms in tight packages where they cannot move of position but they vibrate.

As the temperature increases, the substance and the atoms gain energy and the vibration increases (the atoms agitate). Only when the solid melts into liquid the atoms can change of position.  

The formula is (nh4)2co3