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Flashcards in Waves And Radiation Deck (27):
1

Longitudinal waves

Sound

2

Definition of ultrasound

Frequencies above 20000Hz

3

Definition of diffraction

The bending effect of a wave when obstacles are placed in its way

4

Radio waves

Low frequency
Long wavelength

5

Gamma ray

High frequency
Short wavelengths

6

What can radio waves do?

Diffract easily

7

What are microwaves used for

Send signals up to space

8

Example of transverse waves

Light
Water

9

What is infrared used for

Speeds up the healing of muscle tissue
Thermal imaging cameras

10

What is visible light used for

Lasers
Remove birthmarks and tattoos

11

What is ultraviolet used for

Treating skin conditions like acne

12

What are gamma rays used for

Killing cancer cells

13

What is refraction

The process where the speed of a wave changes as it travels from one medium to a different medium

14

What is an alpha particle

2 protons and 2 neutrons
Helium nucleus

15

Beta

A fast moving electron

16

Gamma

An electromagnetic wave

17

What is alpha radiation used for

Smoke detectors

18

What is background radiation

The radiation that is around us all the time

19

What is Activity

Number of decays each second

20

What are some safety precautions when dealing with radiation

Limit the time exposed to radiation
Put a distance between yourself and the radioactive source
Use tongs to lift the source
Never bring radioactive sources close to your bode
Store in lead lined box
Wash hands afterwards

21

What is meant by the term half life

The time taken for the activity of a radioactive source to half its previous value

22

What is fission

When a neutron is fired at a large unstable uranium nucleus which absorbs the neutron and then splits into two smaller nuclei and then causes a chain reaction

23

What is fusion

When two smaller nuclei fuse together to form a large nucleus

24

Advantages of nuclear fission

No greenhouse gases
Stable supply of electricity
Uses a small amount of fuel but creates a large amount of electricity

25

Disadvantages of nuclear fission

Produces nuclear waste that is dangerous for hundreds of years
Expensive to store nuclear waste
Catastrophic events like earthquakes and tsunamis could cause dangerous radiation emissions
Nuclear power station are expensive to build

26

Advantages of fusion

No greenhouse gases
No radioactive waste
Hydrogen as a fuel which is easy to source as it is in water

27

Disadvantages of fusion

Requires temperatures close to the sun to work which is very dangerous