EM spectrum

Question 1

What is the order of EM?

Answer 1

Radio waves, microwaves, IR, Visible light, Ultra violet, x rays, gamma rays. Increasing in frequency and decreasing in wavelength.

Question 2

What are radio waves used for?

Answer 2

Communication

Question 3

What are microwaves sued for?

Answer 3

Communication to and from satellites.

Question 4

How do microwaves heat food?

Answer 4

They are absorbed by water molecules in food. The microwaves penetrate up to a few cm into the food before being absorbed and transferring the energy they are carrying to the water molecules in the food, causing the water to heat up. The water molecules transfer this energy to the rest of the molecules in the food, heating it up quickly

Question 5

What are IR used for?

Answer 5

Used to monitor temperature. The hotter an object is, the brighter it appears. Also used to make things hotter. eg electric heaters

Question 6

Use of visible light?

Answer 6

Fibre optic cables use visible light to transmit data

Question 7

Use of UV?

Answer 7

Tanning, security pens

Question 8

Use of x rays

Answer 8

Medicine, pass easily through the flesh but not through bones or metal. Used to treat canncer as it kills all living cells, especially cancer cells

Question 9

Use of Gamma Rays?

Answer 9

Treat cancer, kill all living cells, medical tracer

Question 10

Dangers of UV

Answer 10

Damages surface cells, can lead to sunburn, blindness, increased risk to skin cancer

Question 11

Dangers of X rays and Gamma?

Answer 11

ionising radiation so can cause gene mutation, cell destruction or cancer.