Particle Model of Matter Flashcards
What is particle theory?
A model explaining how particles behave in solids, liquids, and gases
What holds particles together in a solid?
Strong intermolecular attractive forces
Why can’t solids flow?
Particles are fixed in position and only vibrate
What happens at the melting point?
Particles gain enough energy to break bonds, turning the solid into a liquid
What allows liquids to flow?
Particles are free to move around and are arranged randomly
What happens at the boiling point?
Particles gain enough energy to break all bonds, turning the liquid into a gas
Why do gases fill their container?
Gas particles have very weak attraction forces and move freely
What is random motion in gases?
Particles move in straight lines but are deflected in random directions by collisions
What happens when a gas is cooled?
- Particles lose energy
- Bonds form
- The gas condenses into a liquid
What happens when a liquid is cooled?
- Particles lose energy
- Form bonds
- Freeze into a solid
How does density change in different states of matter?
- Solids: highest density
- Liquids: lower density
- Gases: lowest density
What happens to mass during a state change?
Mass remains the same in a closed system.
Why do gases expand when heated?
Particles gain energy, move faster, and push against the container
What determines the boiling point of a substance?
The energy required to break the bonds between particles in a liquid
What is the formula for density?
Density = Mass ÷ Volume.
