States of Matter Flashcards
What are the three main states of matter?
Solid, liquid, gas.
What determines the state of a substance?
Temperature and intermolecular forces.
What happens during melting?
Particles gain energy and move apart as a solid turns into a liquid.
How does boiling differ from evaporation?
Boiling occurs at a fixed temperature; evaporation can occur at any temperature.
What is sublimation?
The direct change from solid to gas without becoming liquid.
Example: dry ice.
What is deposition?
The direct change from gas to solid without becoming liquid.
Why do gases exert pressure?
Their particles move rapidly and collide with container walls.
Why do solids have a fixed shape?
Their particles are in a fixed, closely packed arrangement.
What is the difference between diffusion and osmosis?
Diffusion is the movement of particles in gas/liquid; osmosis is water movement across a membrane.
How does temperature affect diffusion?
Higher temperatures increase diffusion speed.
Why does diffusion occur faster in gases than in liquids?
Gas particles move more freely and have more energy.
What is Brownian motion?
The random movement of particles in a fluid due to collisions.
Why do different gases diffuse at different rates?
Lighter gases diffuse faster due to lower molecular mass.
Why do liquids take the shape of their container?
Their particles move freely but remain closely packed.
What is the kinetic particle theory?
It explains states of matter based on particle movement and energy.
Why does boiling require more energy than melting?
It requires breaking all intermolecular forces, not just weakening them.
What happens when a gas is cooled?
It condenses into a liquid as particles lose energy.
Why do solids expand when heated?
Particles vibrate more and take up more space.
What is a cooling curve?
A graph showing temperature changes as a substance cools.
What does a flat section on a heating curve represent?
A state change where energy is used to break bonds, not raise temperature.
How does pressure affect the boiling point of a liquid?
Higher pressure increases boiling point.
Why does ice float on water?
It is less dense due to its open hexagonal structure.
What is meant by volatility?
The tendency of a substance to evaporate easily.
Why do ionic compounds have high melting points?
Strong electrostatic forces between ions require high energy to break.
