Electromagnetic Spectrum

Question 1

What is an electromagnetic wave?

Answer 1

A transverse wave caused by oscillations in an electromagnetic field.

Question 2

All electromagnetic waves:

Transfer energy as _____________ from the source of the waves to an absorber.

Can ________________________ such as in space.

Travel at the __________________________ through a vacuum or the air.

Answer 2

radiation

travel through a vacuum

same speed of 3.0 x 10 8

Question 3

What is the order of the electromagnetic spectrum from lowest frequency to highest frequency:
(Red Monsters Imitate Vampires Under Xylophones Graciously)
1.
2.
3.
4.
5.
6.
7.

Answer 3

1. Radio waves
2. Microwaves
3. Infrared radiation
4. Visible light
5. Ultraviolet radiation
6. X-rays,
7. Gamma rays

Question 4

In the electromagnetic spectrum, the lower the frequency, the ___________________ and the ________________.

The higher the frequency, the __________________ and ___________________.

Answer 4

longer the wave
lower the energy

shorter the wave
higher the energy

Question 5

Why are radio waves suitable for communication?

Radio waves are ___________________ through air. They do not cause ____________________ by the human body, and they can be _____________ to _____________________.

Answer 5

transmitted easily
damage if absorbed
reflected
change their direction

Question 6

Radio waves can be produced by oscillations in electrical circuits.

When radio waves are _______________________, they create an ____________________.

This electrical current has the ___________________________________.

________________________________ before transmission, which can then be _____________ when the wave is received to broadcast information.

Answer 6

absorbed by a conductor
alternating current

same frequency as the radio waves

Information is coded into the wave
decoded

Question 7

Microwaves have frequencies which are easily absorbed by molecules in food.

What happens to the internal energy of the molecules and what does it cause?

Answer 7

The internal energy of the molecules increases when they absorb microwaves, which causes heating.

Question 8

Infrared light has frequencies which are absorbed by some chemical bonds.

The internal energy of the bonds increases when they absorb infrared light, which causes heating.

What 2 things is infrared light used for?

Answer 8

Electric heaters and thermal imaging.

Question 9

Ultraviolet waves, X-rays and gamma rays can ___________________________, producing electrically charged ______.

Answer 9

add or remove electrons
ions

Question 10

What are 2 health effects of electromagnetic waves:

Ultraviolet waves can increase the risk of ______________.

X-rays and gamma rays can cause the _________________, which can lead to _________.

Answer 10

skin cancer

mutation of genes
cancer

Question 11

Explain why X-rays can be used to produce images of the bones inside the body. (2)

Answer 11

X-rays are absorbed by bone.
But can pass through flesh.

Question 12

Explain how electrical signals in a transmitter produce a signal in a receiver. (3)
The ________________ in the transmitter also produces ________________.
Radio waves are __________ by the receiver when __________ the ________________ at the same ___________.

Answer 12

electrical current
radio waves
absorbed
inducing
electrical current
frequency