Electromagnetic Radiation

Question 1

They have the longest wavelengths and the lowest frequencies in the electromagnetic spectrum. They can be produced by making electricity oscillate in an aerial, or antenna, and are used to transmit sound and picture information over long distances.

Answer 1

Radio and TV waves

Question 2

These are radio waves of very short wavelength. They are used in satellite communications because they can penetrate the ionosphere – a layer of the earth’s atmosphere in which there is a high concentration of charged particles.

Answer 2

Microwaves

Question 3

These are waves that lie in the region beyond the red end of the visible spectrum. Their wavelength is too long to be visible to the naked. Its radiation is most noticeable when given off by hot objects, especially when objects are red hot.

Answer 3

Infrared Waves

Question 4

At about 700^oC, the shortest waves present can be detected by the eye. These are what we know as light waves. They make up only a small portion of the entire electromagnetic spectrum.

Answer 4

Visible Waves

Question 5

These waves are invisible radiation that lie beyond the violet end of the visible spectrum. They have a shorter wavelength than violet light and carry more energy.

Answer 5

Ultraviolet Waves

Question 6

These waves are invisible radiation that lie beyond the violet end of the visible spectrum. They have a shorter wavelength than violet light and carry more energy.

Answer 6

Ultraviolet Waves

Question 7

They have short wavelengths and high frequencies and are very penetrating. They are produced by the rapid acceleration of electrons in X-ray machines that collide with atoms.

Answer 7

X-rays

Question 8

They can penetrate through flesh but not bone
are used in X-ray photography to help doctors look inside the body.

Answer 8

X-rays

Question 9

They are high-energy waves produced from nuclear reactions. They have shorter wavelengths than X-rays because energy changes within the nucleus are normally much larger than those that take place outside it.

Answer 9

Gamma Rays

Question 10

They are more dangerous than X-rays because radioactive substances emit them.

Answer 10

Gamma Rays

Question 11

It is our main source of ultraviolet light.

Answer 11

Sun

Question 12

It is most noticeable when given off by hot objects, especially when objects are red hot.

Answer 12

Infrared Radiation

Question 13

This color has the shortest wavelength.

Answer 13

Violet

Question 14

This color has the longest wavelength.

Answer 14

Red