States of matter

• Pressure is caused by gas molecules colliding with the walls of their container.
• Gas particles are far apart, have high speeds, move randomly, and collide with one another frequently.
• The kinetic theory explains the properties of gases.
• Solids have high density because the particles are packed tightly together.
• In solids, the particles are tightly packed together with strong forces between them, resulting in high potential energy.
• Liquid molecules are close together, but they can slide past one another.
• Gases have no fixed volume or shape because they are made up of individual particles that move freely.
• Liquids have a definite volume but can take any shape to fit into the container.
• The kinetic theory explains why gases expand when heated and contract when cooled.
• Increasing temperature increases the average speed of gas particles.
• Increasing temperature increases the average speed of gas particles, causing them to collide more forcefully with the container's walls.
• Decreasing temperature decreases the average speed of gas particles, resulting in less frequent collisions with the container's walls.
• Decreasing volume decreases the average distance between gas particles.
• Liquids have lower densities than solids but higher densities than gases due to intermolecular forces between particles.
• At low temperatures or pressures, most gas particles will be moving slowly and not collide very often.
• States of matter include solid, liquid, and gas.
• Density can be calculated using mass divided by volume (g/cm3).