Solids molecules are tightly held together in close bonds,they could bend or vibrate but still stay bonded. So they have little k.e Liquid molecules are much loser than solid,its bond are flexible enough to slide over eachother. So it has greater k.e compared to solid Gas molecules are the most loosed,they take the shape of the container thus its molecules moves freely colliding btw themselves and its container. So gas has the greatest k.e amongs the rest