Medium Matt through which energy may travel
Thunder and lightning are both types of waves
Can be solid, liquid, or gas
Electromagnetic Spectrum
A continuum of all electromagnetic waves arranged according to frequency and wavelength, from radio waves to gamma radiation
Waves
Can be categorized as either mechanical or electromagnetic
Electromagnetic Waves
Do not need a medium and can transfer energy in a vacuum
Form when electromagnetic fields oscillate instead of when a medium such as air or water vibrates
Result of vibrations in an electromagnetic field
Typically travel faster than mechanical waves
Reason why you see a lightning strike before you hear thunder (caused by lightning)
Examples
Radio waves, X-rays, Gamma Rays, Ultraviolet Rays, Visible Light Rays, Microwaves
Mechanical Waves
Waves that need a medium to travel through to carry energy from one point to another
Can not travel or carry energy in a vacuum
A vibration of molecules in physical matter
Examples
Sound or Water Waves
Sound Waves
Can travel through various mediums
Commonly think of sound traveling through air, over copper wires, through glass fibers, or even through a string
Respond differently to each type of medium such as moving rapidly through some mediums while slowing down through others
Example:
Geophysicists measure the time it takes sound to travel through the various layers of Earth to identify the types of rocks when searching for oil and gas?

answers-
a-because they have to live right
b- because the light is better
c-because the brighter the light is , the greater