Electromagnetic Spectrum

By Ms. Merrikin

wave- up and down movement of energy from one place to another

electromagnetic waves (EM waves)-• Electric and magnetic energy • travel through empty space• Stars (our sun) emit every type of EM wave.

electromagnetic spectrum (EMS)- a diagram showing the waves from longest to shortest wavelength

Extra Credit Assignment: Find and print your own EMS diagram for your notes Illustrate and draw your own EMS diagram using your notes.

Humans can only see VISIBLE LIGHT

Humans can only feel Infrared Energy (IR)

What can we sense?

Wave Name Properties / Effects

Uses Interesting Facts

Radio

Micro

Infrared

Visible

Ultraviolet

X-Ray

Gamma

RADIO WAVES

USES: MRI Scans, Radio signals, TV broadcast, satellite communications. Emitted by radio antennae and by stars. May be sent by aliens?

EFFECTS: They have the lowest energy, so they are harmless.

Microwavesrowavesves

USES: Cell phones, radar, cooking.Effects: Possible link between cell phones and brain tumors

Infrared Waves

USES: fast food heat lamps, finding people in the dark, measuring temperature

SOURCES: anything warm

Infrared spy camera

VISIBLE LIGHT - the only EM waves humans can SEE!

Makes up only a very small part of the EM spectrum!

Has medium wavelength and medium energy, so it is not harmful to organisms.

Ultraviolet (UV) Waves

USES: tanning and hand dryers for bacteria disinfection, dentistry

EFFECTS: Has more energy than visible light, so it may damage skin cells, may cause cancer

SOURCES: Stars and UV lights (like the SUN)

Skin cancer on a man’s arm

X-RAYS

Airport Security Body Scans and Luggage Scans

X-Ray Image of the Sun

USES: to see inside the body, to see inside luggage, to kill cancer cells, sterilize medical equipment

EFFECTS: Has a lot of energy, so it may damage DNA, may cause cancer

X-RAYS USES

GAMMA RAYS

Mushroom cloud from atomic bomb

EFFECTS: may damage DNA, may lead to cancer or radiation sickness

SOURCES: radioactive elements (U, Ra, Cs-137, Ir-92, Co-60,K-40,Tc-99), nuclear explosions, stars, supernovae

GAMMA RAYS

Nuclear Medicine – Patient is injected or drinks radioactive dyes that they can scan for

Food Sterilization

USES: see inside the body, measure blood flow, kill cancer cells (radiation therapy), measure the thickness of metal, find leaks in pipes, strengthen materials, sterilize food & medical equipment, measure properties of rock and soil.

GAMMA RAYS