Physical Science / Unit 2: Properties and States of Matter
2.3 States of Matter
Notes
The kinetic theory says all matter is made of tiny particles that are always moving.
- Solid: particles vibrate in fixed positions; definite shape and volume.
- Liquid: particles slide past each other; definite volume, takes the shape of its container.
- Gas: particles move freely and far apart; no definite shape or volume.
- Plasma: hot, electrically charged gas found in stars and lightning.
- Higher temperature means higher average particle kinetic energy.
Practice
Which state of matter has a definite volume but no definite shape?
Liquid particles flow, so the liquid takes the container's shape but keeps its volume.
Why can a gas be compressed much more easily than a liquid?
The space between gas particles lets them be pushed closer.
As a solid is heated, its particles:
Added thermal energy increases particle motion.
Ready for more? Take the Unit 2 test.