1. Physical Science Chapter 3
States of Matter

2. Section 3.1 Solids, Liquids, & Gases
Materials are based as solid, liquid, or gas based on whether their shapes and volumes are definite or variable.

3. Solids
Solid is the state of matter in which materials have a definite shape and a definite volume.
Atoms are packed closely together.
Almost all solids have orderly arrangement of particles at atomic level.

4. Liquids
Liquids have a definite volume but not a definite shape.
Takes on the shape of the container.
Atoms are close together but arrangement is more random than in a solid.

5. Gases
A gas takes on the shape and volume of its container.
Atoms not arranged in a particular pattern.
More easily compressed.

6. Other States of Matter
Plasma – super-heated gas, makes up ~99% of matter in the universe
Bose-Einstein condensate – at temperatures near -273oC groups of atoms act as a single particle

7. Kinetic Theory
Kinetic energy is the energy an object has due to its motion.
Faster the object moves, the greater its kinetic energy.
States that all particles of matter are in constant motion.

8. Motion in Gases Gas particles move at an average of 1600 km/hr.
Can slow down or speed up, but total kinetic energy stays the same.
There are forces of attraction among the particles in all matter.
But, particles moving too fast to have an effect.

9. Kinetic Theory of Gases
The constant motion of particles in a gas allows a gas to fill a container of any shape or size.
3 Main Points:
Particles in a gas are in constant, random motion.
Particles are unaffected unless they collide.
Forces of attraction can be ignored under ordinary conditions.

10. Behavior of Liquids
Particles in liquids are closely packed so attraction between particles do affect movement of particles.
Liquid takes the shape of its container because particles in a liquid can flow to new locations.
Volume is constant because forces of attraction keep the particles close together.

11. Behavior of Solids
Solids have a definite volume and shape because particles in a solid vibrate around fixed locations.

12. 3.2 The Gas Laws
Pressure is the result of a force distributed over an area.
Pressure = Force measured in newtons and area in square meters = Pascal (Pa) = N/m2 very small, usually expressed as kPa
Collisions between particles of a gas and the walls of the container cause the pressure in a closed container of gas. More collisions, greater pressure.

13. Factors that Affect Gas Pressure
Temperature
Volume
Number of Particles

14. Temperature
Raising the temperature of a gas will increase its pressure if the volume of the gas and the number of particles are constant.
Temperature rises, kinetic energy rises, number of collisions increase, greater force
T ↑ P ↑

15. Volume
Reducing the volume of a gas increases its pressure if the temperature of the gas and the number of particles are constant.
V ↓ P ↑

16. Number of Particles
Increasing the number of particles will increase the pressure of a gas if the temperature and volume are constant.
n ↑ P ↑

17. Charles’s Law
States that the volume of a gas is directly proportional to its temperature in kelvins if the pressure and the number of particles of the gas are constant.
V1/T1 = V2/T2

19. A sample of gas occupies 3. 5 L at 300 K
A sample of gas occupies 3.5 L at 300 K. What volume will it occupy at 200 K?
V1 = 3.5 L, T1 = 300K, V2 = ?, T2 = 200K
Using Charles’ law: V1/T1 = V2/T2
3.5 L / 300 K = V2 / 200 K
V2 = (3.5 L/300 K) x (200 K) = 2.3 L

20. Boyle’s Law
States that the volume of a gas is inversely proportional to its pressure if the temperature and the number of particles are constant.
P1V1 = P2V2

22. A sample of carbon dioxide occupies a volume of 3
A sample of carbon dioxide occupies a volume of 3.50 liters at 125 kPa pressure. What pressure would the gas exert if the volume was decreased to 2.00 liters?
(125 kPa)(3.50L) = 219kPa
2.00L

23. Combined Gas Law
Describes the relationship between the temperature, volume, and pressure of a gas when the number of particle is constant.
P1V1/T1=P2V2/T2
Problem page 80