A: The forces between liquid particles are weaker than the forces between solid particles. This means that liquid particles are further apart and can move about more easily. Since the particles can move, the liquid can flow and take the shape of its container.
B: When heat is added to a substance, the molecules and atoms vibrate faster. As atoms vibrate faster, the space between atoms increases. The motion and spacing of the particles determines the state of matter of the substance. Solids,liquids and gasses all expand when heat is added.
