How does the strength of intermolecular forces vary in different states?

The strength of intermolecular forces varies, being strongest in solids, weaker in liquids, and weakest in gases.

In solids, the particles are closely packed together and have a fixed position, which means they vibrate about a fixed point but do not move from place to place. This close proximity and lack of movement allow for strong intermolecular forces. These forces are what keep the particles in a fixed, rigid structure. The strength of these forces is what gives solids their definite shape and volume.

In liquids, the particles are still close together but they are not in a fixed position. They can move around each other, which means the intermolecular forces are weaker than in solids. However, they are still strong enough to keep the particles close together, which is why liquids have a definite volume but not a definite shape. They take the shape of the container they are in because the particles can move around, but they cannot expand to fill the container because the intermolecular forces keep them together.

In gases, the particles are far apart and move freely in all directions. This means the intermolecular forces are very weak, almost negligible. The particles in a gas have enough energy to overcome the intermolecular forces that would otherwise keep them close together. This is why gases do not have a definite shape or volume. They will expand to fill any container they are in because there are no significant intermolecular forces to keep the particles together.

In summary, the strength of intermolecular forces is determined by the state of the substance. The closer the particles and the less they move, the stronger the intermolecular forces. This is why solids have the strongest intermolecular forces, followed by liquids, and then gases with the weakest.