Since there is no diagram I can see to prove my answer, I must infer that a heat source should be applied to the solid substance and cause the atoms in the solid to spread further apart and become a different state, in which atoms will be able to freely move, gas.
Claim 2: Molecules speed up when they get energy from other molecules and slow down when they give energy to other molecules.
Energy can’t be destroyed (stated in claim 1) so claim 2 is more than likely to be correct