Electromagnet Spectrum Study Guide

in book pg 31-41 and in INB pg 84-90

Electromagnetic spectrum

Electromagnetic spectrum

range of frequencies of electromagnetic radiation and their respective wavelengths and photon energies

Radiation

Transfer of energy as EM waves

Photons

Radiant energy that travels through space in particle-like units. They have no mass

What is the order of the Electromagnetic Spectrum. Lowest → Highest

Radio, Microwaves, Infrared, Visible Light, Ultraviolet, X-rays, Gamma Rays

Radio waves

Lowest frequency and highest wavelength. Used for radio transmissions, tv signals, cell phones.

Microwaves

Higher frequency and lower wavelength than radio waves. Used for cooking food, radar, satellites, and MRI's

Infrared waves

Higher frequency and lower wavelength than microwaves. Used for remote controls

Visible light

All the colors you are able to see

Ultraviolet waves

Higher frequency and lower wavelength than visible light. Used to get vitamin d, can give you a sun burn

X-rays

Higher frequency and lower wavelength than UV waves. Used to see internal pictures

Gamma rays

Highest frequency and lowest wavelength in the EM spectrum. Used for cancer treatment

As you go from left (highest) → right (lowest) across the electromagnetic spectrum what happens to the frequency and energy of the waves?

the wavelengths get smaller and the frequencies get higher

Absorption

Transfer of light energy particles of matter

What color absorbs all colors?

Black

What color reflects all colors?

White

Scattering

Interaction of light with matter that causes light to change its direction, energy, or both

Reflection

Occurs when a wave hits another wave or object that it cannot pass through and bounces back

Refraction

Occurs when a wave passes from one medium to another at an angle and bends due to a change in speed

Diffraction

Occurs when a wave passed through an opening and spreads out

What are the colors and order of the visible light? Lowest → Highest

red, orange, yellow, green, blue, indigo, violet

~

Red has the lowest frequency and highest wavelength violet has the highest frequency and lowest wavelength

ROY G BV

Electromagnetic Waves can travel through a vacuum a medium, or empty space

true

What happens when light travels/passes through one medium to another?

The denser the medium is, the slower the light moves through it. This is basically how refraction works since the different mediums change the way it reflects.

Why might we only see a specific colors through a filter instead all of the visible light?

The filter only reflects the same color as the filter

How do we know our brain doesn’t send light waves through our eyes to objects, but instead the light waves reflect of an object to our eyes?

if our brain sent light waves through our eyes, we would be able to see in the dark

what units are used to measure the distance between crest and trough?

meters (m)

what units are used to measure the frequency?

hertz (hz)