Using the kinetic theory , explain why a solid has a definite shape and liquid has none.
The kinetic theory of matter states that particles in matter, which can be atoms or molecules, are in constant motion. These different states of matter, such as solids, liquids, and gases, can be explained by comparing the energy of the particles, the forces between them, and their relative freedom of movement.
In solids, the particles have a low average kinetic energy, which means they vibrate around fixed positions but don't have enough energy to move out of those positions. The attractive forces between the particles are strong and hold them close together in a regular, organized pattern called a crystal lattice. This fixed arrangement gives the solid a definite shape and volume. The particles move only around their mean positions with limited freedom.
On the other hand, in liquids, the particles have a higher average kinetic energy than in solids, which allows them to move more freely. The attractive forces between the particles are strong enough to keep the particles close together, but not strong enough to hold them in fixed positions like in solids. This means that the particles in a liquid can flow past one another more easily, resulting in a state where a liquid can take the shape of its container but still maintain a definite volume.
To sum up, the definite shape of a solid is a result of the strong intermolecular forces that hold the particles in fixed positions within the crystal lattice, restricting their movement to vibrations around a fixed position. In contrast, a liquid has no definite shape because the particles move more freely than in a solid, with the intermolecular forces being strong enough to maintain a definite volume but not strong enough to hold the particles in a fixed, regular arrangement.