Chapter 14: The Electromagnetic Spectrum

Question 1

What is the order of the electromagnetic spectrum in terms of wavelength from longest to shortest?

Answer 1

Radiowaves, microwaves, infra-red, visible light, UV, X-rays, gamma rays

Question 2

What is the electromagnetic spectrum?

Answer 2

a continuous range of electromagnetic waves

Question 3

How do you work out the wave speed?

Answer 3

wave speed = frequency x wavelength

Question 4

What type of wave are the waves in the electromagnetic spectrum?

Answer 4

They are transverse.

Question 5

What speed do the waves in the electromagnetic spectrum travel at?

Answer 5

The speed of light: 3x10^8

Question 6

Give examples of the uses of radiowaves

Answer 6

Broadcasting and communications - can easily travel around the world because of its long wavelength

Question 7

Give examples of the uses of microwaves

Answer 7

Satellite transmissions because it can carry large amounts of data

Question 8

Give examples of the uses of infra-red waves

Answer 8

Heater and night vision equipment and remotes because it is easy to make and control

Question 9

Give examples of the uses of visible light

Answer 9

It is used for human vision, because our eyes are sensitive to this type of light

Question 10

Give examples of the uses of ultraviolet waves

Answer 10

It is used in fluorescent lights because it is very bright and colourful. It can also be used to kill bacteria and other microbes.

Question 11

Give examples of the uses of X-rays

Answer 11

It is used in medical equipment because it can help radiologists see defects or breaks in bones.

Question 12

Give examples of the uses of gamma rays

Answer 12

It is used in sterilising food because it can kill bacteria, and it is also used in medical equipment because it can detect defects in solid objects

Question 13

What can too much exposure to radiowaves do to the human body?

Answer 13

Radiowaves do not seem to cause much damage.

Question 14

What can too much exposure to microwaves do to the human body?

Answer 14

Microwaves cause internal heating of body tissues.

Question 15

What can too much exposure to infra-red waves do to the human body?

Answer 15

Infra-red radiation is felt as heat and can cause skin burns.

Question 16

What can too much exposure to visible light do to the human body?

Answer 16

Nothing - we use it to see.

Question 17

What can too much exposure to ultraviolet light do to the human body?

Answer 17

Ultraviolet can cause skin cancer and sunburn.

Question 18

What can too much exposure to X-rays do to the human body?

Answer 18

They can damage cells, cause mutations leading to cancer, and cause cell death.

Question 19

What can too much exposure to gamma rays do to the human body?

Answer 19

Gamma rays, like X-rays, can also damage cells, cause mutations leading to cancer and causes cell death.