The Electromagnetic Spectrum: Pages 53 and 54

QUESTION: What is a spectrum?

OBJECTIVE: Students will be able to name and give a common use of waves that make up the electromagnetic spectrum.

VOCABULARY: spectrum electromagnetic spectrum

The Electromagnetic SpectrumWrite these questions onto pages 53 and 54

SKIP ONE LINE BETWEEN EACH QUESTION

1. What is the relationship between the frequency of a wave and its energy? (Skip three lines)

2. What is a common use of these waves: radio waves, microwaves, infrared rays, ultraviolet rays, x-rays and gamma rays?

3. What basic colors makeup visible light?

What is the Electromagnetic Spectrum?The electromagnetic spectrum is a range of waves.

The electromagnetic spectrum arranges waves from the lowest frequency to the highest frequency. DRAW AND LABEL THE SPECTRUM

THE HIGHER A WAVES FREQUENCY, THE GREATER

ITS ENERGY

Waves of the Electromagnetic Spectrum

There is one kind of electromagnetic wave we can see.

Visible light waves

Most electromagnetic waves are invisible. infrared rays

microwaves ultraviolet waves

X-rays radio waves

gamma rays

Radio WavesRadio waves have the lowest frequency and longest wavelength of any wave

Radio waves carry radio and television signals from the station to our homes

MicrowavesMicrowaves have many uses.

Microwaves not only can be used to quickly heat food, but they are also used to carry cell phones signals and by police in their speed guns.

Infrared RaysInfrared rays are felt by usas heat. Much of the energy from the Sun reaches Earth as infrared rays.

Special infrared cameras can show the heat being given off by objects. Hotter objects are shown as lighter colors and cooler objects are shown as darker colors.

Visible LightA very small part of the electromagnetic spectrum is able to be seen by humans.

Only visible light can be seen by us. White light is really a mixture of all the colors of the spectrum.

A piece of glass called a prism can separate white light into the colors of the spectrum.

Ultraviolet RaysUltraviolet rays mostly come to us from the Sun.

Small amounts of ultraviolet rays help our bodies produce vitamin D, but too many of these rays can cause sunburn, skin cancer and eye damage.

X-RaysX-rays have high frequencies. They carry enough energy to go through most matter.

Because x-rays can go through most matter, they are used by doctors to look at bones inside the body. X-rays cannot go through bones or metal.

Gamma RaysGamma rays have the highest frequencies of any waves. These rays are given off by distant stars. Fortunately, these our atmosphere filters out these rays before they reach Earth.

Gamma rays carry so much energy that they are extremely dangerous. Gamma rays are used to kill cancer cells in the body.

The Electromagnetic Spectrum: p. 53, 54Check that the answers to these

questions are in your notes.

1. What is the relationship between the frequency of a wave and its energy?

2. What is a common use of these waves: radio waves, microwaves, infrared rays, ultraviolet rays, x-rays and gamma rays?

3. What basic colors makeup visible light?

VOCABULARYSpectrum- a range of related objects.

Electromagnetic Spectrum- a complete range of electromagnetic waves in order from lowest frequency to highest.