Electromagnetic Waves

Question 1

What is electromagnetic waves?

Answer 1

Transverse waves.

All electromagnetic waves can:

• Transfer energy as radiation from the source of the waves to an absorber.
• Can travel through a vacuum like Space.
• Travel at the same speed through a vacuum or air

Question 2

Electromagnetic Spectrum

Answer 2

Long wavelength = low frequency = low energy

Short wavelength = high frequency = high energy

The higher the frequency, the more hazardous the wave is.

Question 3

Radio Waves

Answer 3

Used for communications, ie; broadcasting, television and radio.

Transmitted easily through air and do not cause damage to the human body if absorbed.

Question 4

Micro Waves

Answer 4

Used for cooking foods, communication etc.

Intense microwaves can cause internal heating of body cells.

Question 5

Infrared Waves

Answer 5

Used by electrical heaters, cooker for cooking food, remote controls etc.

The heating effect of IR’s can cause burns to the skin.

Question 6

Visible Light

Answer 6

Light we can see which is used in photography and illumination.

Question 7

Ultraviolet (UV)

Answer 7

We cannot see UV light but it can have hazardous effects on the human body.

Causes skin to tan or burn.

Can be used to check forgery for bank notes.

The hazardous properties of UV means that it can kill bacteria and so is used to disinfect water,

Question 8

X-Rays

Answer 8

Used to scan internal structures of objects and airport scanning.

Can cause mutations of genes which leads to cancer.

Question 9

Gamma Rays

Answer 9

Used for sterilising food and medical instruments, and in the detection and treatment of cancer.

Can cause mutations of genes which leads to cancer.

Question 10

Ionising Radiation

Answer 10

UV, x-rays, gamma rays are types of ionising radiation. They can add or remove electrons from molecules to create electrically charged ions