This document discusses the classification and properties of matter. It describes how matter can be classified based on physical nature into solids, liquids, and gases, and based on chemical nature into elements, compounds, and mixtures. The key differences between the three physical states - solid, liquid, and gas - are explained in terms of intermolecular forces and distances, and kinetic energy of particles. Solids have the smallest intermolecular spaces and strongest forces, while gases have the largest spaces and weakest forces.