Explain why atoms move at different speeds depending on whether they are in liquid or solid

If they are in a solid state the atoms are aligned together, they are tightly packed, have a solid for, but do move they just move so slow that they just vibrate because like I've said they are tightly packed and can't move much. If they are a liquid the have a lot of space so they move around making the speed faster

Because in difrent materials atoms are more compact or less compact. if they are less compact then it will be easear for them to move