1.5 Electromagnetic Waves

Question 1

Are all the waves in the electromagnetic spectrum transverse or longitudinal?

Answer 1

Transverse

Question 2

What is a mnemonic to remember the order of the electromagnetic spectrum?

Answer 2

Raging Martians Invaded Venus Using X-ray Guns

Question 3

When in a vacuum, what speed do the electromagnetic waves travel at?

Answer 3

3 x 10^8 m/s

Question 4

In different mediums, waves travel at different speeds. What does this usually lead to?

Answer 4

Refraction

Question 5

Those with shorter wavelength, have higher _____________

Answer 5

frequencies

Question 6

What two things in waves are inversely related?

Answer 6

Wavelength and frequency, if one goes up the other will go down

Question 7

Which part of the electromagnetic spectrum is the only part we are able to detect with our eyes

Answer 7

Visible light

Question 8

What colours are in visible light and how would you remember the order?

Answer 8

R - Red
O - Orange
Y - Yellow
G - Green
B - Blue
I - Indigo
V - Violet

Question 9

Which are the ionising waves in the electromagnetic spectrum?

Answer 9

Ultraviolet, X-Rays, Gamma rays

Question 10

What is white light?

Answer 10

A mixture of all of the colours across the visible spectrum

Question 11

EM waves spread out from a source and transfer energy to an __________

Answer 11

absorber

Question 12

When you warm yourself by an electric heater, where do infrared waves transfer energy from?

Answer 12

The thermal energy store

Question 13

The higher the frequency of the EM wave, the more _______ it transfers

Answer 13

Energy

Question 14

What is radioactive decay?

Answer 14

Changes in nuclei that cause gamma rays to be emitted

Question 15

How are visible light, UV and X-rays emitted?

Answer 15

They’re emitted when electrons drop down energy levels

Question 16

How is infrared radiation emitted?

Answer 16

They’re emitted when the bonds holding the atoms together in molecules vibrate

Question 17

What happens when any type of EM wave is absorbed?

Answer 17

It ceases to exist as radiation and causes heating

Question 18

What happens when high energy UV, X-rays and gamma rays are absorbed by atoms?

Answer 18

They have so much energy that they don’t just cause heating, but can cause ionisation when they’re absorbed by atoms

Question 19

What is infrared radiation absorbed by?

Answer 19

Molecules

Question 20

What is UV radiation from the Sun absorbed by?

Answer 20

The oxygen molecules in the upper atmosphere, forming Ozone. This ozone then absorbs large amounts of ionising UV radiation from the Sun, protecting living things (especially animals) from its damaging effects

Question 21

Which types of electromagnetic waves can be used in communication? (2)

Answer 21

Radio waves, Microwaves

Question 22

Electromagnetic waves can be: (3)

Answer 22

• Reflected
• Absorbed
• Transmitted