Learn: States of Matter

Welcome!Today we'll explore states of matter, an essential topic in chemistry. We'll learn about solids, liquids, and gases, and how particles behave in these states. Let's get started!

What are States of Matter?Substances exist in different forms called states of matter. These are solid, liquid, and gas. The state of a substance depends on the arrangement, movement, and energy of its particles, as well as the temperature and pressure.

SolidsIn a solid, particles are closely packed together in a fixed, regular arrangement. They vibrate but do not move freely. Solids have a definite shape and volume, and they are usually not compressible.

LiquidsIn a liquid, particles are still close together but can move past each other, allowing liquids to flow. Liquids have a definite volume but can take the shape of their container. They are not easily compressed.

GasesIn a gas, particles are far apart and move freely and quickly. Gases don't have a definite shape or volume, and they expand to fill the container they're in. They are compressible because there is space between the particles.

Interconversion of StatesSubstances can change from one state to another through processes called interconversions. For example, melting turns a solid into a liquid, and boiling turns a liquid into a gas. These changes occur due to changes in temperature and pressure.

Particle Changes During InterconversionWhen a substance changes state, the particles gain or lose energy. For example, during melting, the particles in a solid absorb heat energy, which allows them to move more freely and form a liquid. During freezing, particles lose energy and settle into a fixed structure.

Evidence of DiffusionDiffusion is the movement of particles from an area of high concentration to low concentration. You can observe diffusion in gases, such as when you smell perfume spreading across a room, or in liquids, like ink spreading in water.

Solvent, Solute, SolutionA solvent is the liquid in which a substance dissolves. A solute is the substance that dissolves in the solvent. Together, they form a solution. For example, salt dissolved in water creates a solution.

Review Time!Great work! You've learned about the three states of matter, their interconversions, and the concepts of solute, solvent, and solution. Now let's test your understanding with a few questions.