1. States of Matter Review
Ch. 3

2. States of Matter Solid Liquid Gas Plasma
These are PHYSICAL states of matter – the matter/molecules and atoms are not changing, just their level of ENERGY and temperature.

3. What is temperature?
The AVERAGE kinetic energy (energy of motion) of the molecules or atoms in a sample of matter.
= sum of energy of all atoms and molecules
number of atoms and molecules

5. Solids
Particles close together; cannot change position, so the volume and shape remain constant; only vibrating movement
Liquids
Particles still close together; can move around and slide over each other; volume stays constant, but liquids take the shape of the container

7. Gases
Particles farther apart; higher energy, moving around and bumping into each other; spread out around whatever space given so volume changes, as well as shape
Plasma
Similar to a gas, plasma particles are free-moving, but these are in a higher energy state and some become electrically charged which makes this phase different

9. Changing Phases Vocab

10. Freezing – changing from a liquid to a solid
Melting – changing from a solid to a liquid
Freezing/Melting Point – the TEMPERATURE at which freezing or melting occurs
Vaporizing – changing from a liquid to a gas
Condensing – changing from a gas to a liquid
Boiling Point – the TEMPERATURE at which vaporizing or condensing occurs

11. How is evaporation different from vaporization?
Evaporation occurs on the surface of a liquid, when those molecules acquire enough energy to change phase; doesn’t have to be at the boiling temperature
Vaporization occurs when the substance is at its boiling temperature, and the phase change is occurring with all of the particles

12. Thermal Expansion/Contraction
Solids at warmer temperatures have particles with more energy; the particles then move around a bit more – so they take up a little more space.
Examples???

13. It takes a change in energy for a phase change to occur:
Heat of Fusion
the amount of energy that needs to be added or taken away for melting/freezing; this is different for different substances
Heat of Vaporization
the amount of energy that needs to be added or taken away for vaporization/condensation

14. Heat Calculations Specific heat:
The specific heat is the amount of energy per unit mass required to raise the temperature of a substance by one degree Celsius.
The specific heat of water is 1 calorie/gram °C = joule/gram °C which is higher than any other common substance. As a result, water plays a very important role in temperature regulation. The specific heat per gram for water is much higher than that for a metal.