High EnergyLow Energy
High Frequency Low Frequency
Short Wavelength Long Wavelength
10 5 meters--average radio waves
10 -6 meters begins the visible spectrum.(ROY G BIV)
10 -13 meters--gamma rays
2. Parts of a wave-
Wavelength- The distance between 2 identical parts of a wave
Crest- The highest point of a wave
Trough- The lowest part of a wave
Period- time required for two successive crests or troughs of a wave to pass a given point
3. Interactions of visible light with matter
A. Reflection-
Light rays sent out at the same
angle received.
Wave frequency remains the same
Best reflectors are shiny and light colored surfaces
B. Refraction-
When light rays bend as they
pass from one medium
to another.
Usually caused by differences in
density.
C. Scatter
Waves broken up by
that which it is emitted through.
D. Absorption
The taking in of light energy.
Rough absorbs better than smooth
Black absorbs better than white.
Surfaces that absorb energy best re-radiate energy best.
4. States of matter
A. Phases
1. Solids
a. the molecules or atoms that make up the solid are closely packed together. In a solid the particles are in relatively fixed positions
b. molecules can vibrate, but don’t have complete freedom.
c. if the molecules can move by one another the solid is melting
2. Liquids
a. State of matter in which molecules or atoms are closely packed together. A liquid will assume the shape of its container, but has a fixed volume dependent upon temperature. Molecules in a liquid are in constant motion.
b. if enough energy is added the attraction between the molecules is broken and the liquid is vaporized.
3. Gas
a. Low density phase of matter. A gas has neither fixed volume or shape. It will expand to fill the available volume.
b. if enough energy is added a plasma is created.
4. Plasma
a. Very high energy matter in which some or all of the electrons are removed from the atoms or molecules.
b. the most abundant form of matter in the universe
least abundant on Earth.
c. found in the Stars.
5. Changes in Phase (water)
1. Melting temperature 0 oC
A. Molecules start to vibrate more and more
B. Heat supplied doesn’t raise the temperature
C. Heat is used to break molecules loose from their
position in solids.
D. all molecules must be loose before temperature of liquid goes up
2. Heat of fusion (80 oC cal/gram)
The quantity of heat required to change one gram of solid water to 1 gram of liquid.
3. Boiling temperature (100 oC)
a. To go from 0 oC to 100 oC you need 100 calories
b. at 100 oC an additional 540 calories are absorbed
and used to further pull the molecules apart.
4. Heat of vaporization
The amount of heat required to change 1 gram of liquid water to gas.
a. the temperature does NOT go up during vaporization.
b. latent heat--hidden or unobservable
5. Condensation-
When 540 calories of energy is released as gas changes back to liquid.
6. Freezing Temperature
80 calories are released as liquid turns solid
7. Sublimation- Change directly from a solid to a gas or reverse
** Energy amounts EQUAL in both directions!! **