1. Light Waves Light is an electromagnetic wave.
An electromagnetic wave is a transverse wave that is a transfer of electric and magnetic energy.
The two fields (electric & magnetic) vibrate at right angles to each other.
An electromagnetic wave is made up of vibrating electric and magnetic fields that move through empty space (vacuum) or a medium (matter: solid, liquid, gas) at the speed of light. About 300,000,000 meters per second.
The energy that electromagnetic waves transfer is called electromagnetic radiation.

2. Light and Matter Opaque Translucent Transparent
absorbs or reflects all light
Absorption
When light enters a material but does not leave
It is the transfer of light energy to matter
Translucent
allows some light to pass through
Transparent
allows light to pass through completely

3. Reflection Reflection Normal
when a wave strikes an object and bounces off
incident beam
reflected beam

4. Refraction Refraction Refraction depends on…
bending of waves when passing from one medium to another
caused by a change in speed
Refraction depends on…
speed of light in the medium
wavelength of the light
shorter wavelengths (blue) bend more
Longer wavelengths (red) bend less

5. Visible Light Is all the colors of the EM spectrum we can see.
It narrowest part of the EM spectrum
Roy G BIV (colors of the spectrum)

6. Types of EM Radiation Microwaves Radio waves
Lowest energy EM radiation
FM - frequency modulation
AM - amplitude modulation
Microwaves
penetrate food and vibrate water & fat molecules to produce thermal energy

7. Types of EM Radiation Ultraviolet Radiation (UV)
Infrared Radiation (IR)
slightly lower energy than visible light
can raise the thermal energy of objects
thermogram - image made by detecting IR radiation
Ultraviolet Radiation (UV)
Beyond Violet Light
Ozone layer depletion = UV exposure!
slightly higher energy than visible light
Types:
UVA - tanning, wrinkles
UVB - sunburn, cancer
UVC - most harmful

8. Types of EM Radiation X rays Gamma rays higher energy than UV
can penetrate soft tissue, but not bones
Gamma rays
highest energy on the EM spectrum
emitted by radioactive atoms
used to kill cancerous cells