Chemistry: Matter, Mixtures, and Separation - States of Matter and Kinetic Particle Theory

Matter is anything that has mass and occupies space. It is composed of tiny particles (atoms, molecules, or ions) that are in constant motion, as described by the Kinetic Particle Theory.

Solids: Particles are packed closely together in a regular, fixed lattice arrangement. They vibrate about fixed positions and have very strong intermolecular forces. Solids have a fixed shape and volume.

Liquids: Particles are close together but arranged randomly. They can move and slide over each other, allowing liquids to flow. They have a fixed volume but take the shape of the container.

Gases: Particles are far apart with negligible intermolecular forces. They move rapidly and randomly in all directions. Gases have no fixed shape or volume and are highly compressible.

Phase Changes: Changes in state occur when energy is added or removed. These include melting ($s \rightarrow l$), evaporation/boiling ($l \rightarrow g$), condensation ($g \rightarrow l$), freezing ($l \rightarrow s$), and sublimation ($s \rightarrow g$).

During a phase change, the temperature remains constant. The energy supplied is used to overcome the forces of attraction between particles rather than increasing the kinetic energy ($E_k$).

Diffusion: The net movement of particles from a region of higher concentration to a region of lower concentration due to random motion. The rate of diffusion is affected by temperature ($T$) and the mass of the particles ($m$).

Gas Pressure: Pressure is exerted when gas particles collide with the walls of a container. It is defined as force per unit area: $P = \frac{F}{A}$.