Waves of the Waves of the Electromagnetic Electromagnetic

SpectrumSpectrum

Magnetic Field

Electric Field

Producing EM wavesProducing EM waves

Electric field causes magnetic field to vibrate and magnetic field causes electric field to vibrate.

- Perpendicular to each other

EM radiation – the energy that is transferred by EM waves

General InfoGeneral InfoAll EM waves travel at the All EM waves travel at the same same speedspeed..

However, have However, have differentdifferent wavelengthswavelengths and and frequenciesfrequencies..

The The higherhigher the the frequencyfrequency of a wave of a wave

The The higherhigher its its energyenergy

EM spectrum – Range of EM waves in EM spectrum – Range of EM waves in

order of order of increasingincreasing frequencyfrequency..

Radio WavesRadio WavesLongest Wavelength; lowest frequencyLongest Wavelength; lowest frequency

Includes:Includes:–Broadcast wavesBroadcast waves: Carry signals for radio : Carry signals for radio

and TVand TV

–MicrowavesMicrowaves: : Cook/heat foodCook/heat food

Cell phone communicationCell phone communication

RADAR – uses Doppler effect to calculate RADAR – uses Doppler effect to calculate speed.speed.

Infrared RaysInfrared RaysEx: Invisible heat you feel from a Ex: Invisible heat you feel from a burner on a stove.burner on a stove.

More energy than radio wavesMore energy than radio waves

Heat Lamp uses infrared rays Heat Lamp uses infrared rays (uses very little visible light)(uses very little visible light)

Infrared cameras – Takes pictures Infrared cameras – Takes pictures using IR rays instead of lightusing IR rays instead of light–Makes a Makes a thermogramthermogram

Visible LightVisible LightONLYONLY EM waves you can see EM waves you can see

Longest WL are Longest WL are redred

Shortest WL are Shortest WL are violetviolet

White light is a mixture of many colorsWhite light is a mixture of many colors– Can be separated into colors by a prismCan be separated into colors by a prism

OrangeYellowGreenBlueIndigo

ROYGBIV

Ultraviolet Rays (UV)Ultraviolet Rays (UV)More energy than light – enough to More energy than light – enough to damage or kill living cells!!damage or kill living cells!!

SmallSmall doses are doses are usefuluseful–Causes skin cells to produce Vit. DCauses skin cells to produce Vit. D

LargeLarge doses are doses are harmfulharmful–Burn skinBurn skin

–Cause skin cancerCause skin cancer

–Damage eyesDamage eyes

X-raysX-raysMore energy than UVMore energy than UV–Can penetrate most matter – unless it is Can penetrate most matter – unless it is

too dense such as bone or leadtoo dense such as bone or lead

UsesUses::–Images of bonesImages of bones

–Images of cracks in steel or concreteImages of cracks in steel or concrete

HarmfulHarmful if too much exposure to X- if too much exposure to X-raysrays–can cause cancercan cause cancer

Gamma RaysGamma RaysMost energy of all waves – most Most energy of all waves – most penetrating – penetrating – most dangerousmost dangerous!!

Produced by:Produced by:– Some radioactive substancesSome radioactive substances

– Certain nuclear reactionsCertain nuclear reactions

UsesUses::– Medical – can be used to kill cancer cellsMedical – can be used to kill cancer cells

– Can be injected to form an image of inside of Can be injected to form an image of inside of bodybody