HEALTH Nuclear Radiation

Question 0

What can nuclear radiation be used for?

Answer 0

To sterilise medical equip,net by killing germs and to kill cancerous cells (using a beam of gamma rays from different directions so that surrounding tissue is not harmed).

Question 1

What effect does radiation have on living cells?

Answer 1

It kills them,

Question 2

Why can radiation be used as tracers?

Answer 2

They emit waves so can be detected and a picture boult up using a gamma cameraThey are specifically chosen for the organ that is being investigated.

Question 3

How is alpha radiation affected in air and what is it absorbed by?

Answer 3

20cm in air and a sheet of paper

Question 4

How is beta radiation affected in air and what is it absorbed by?

Answer 4

Few meters, 2-3mm of aluminium

Question 5

How is gamma radiation affected in air and what is it absorbed by?

Answer 5

Not absorbed, 2-3cm of lead

Question 6

Why a happens when radiation passes through a material?

Answer 6

Some of it is absorbed (depending on the radiation and material as to how much)

Question 7

Describe an atom

Answer 7

Orbiting electrons and a nucleus containing protons and neutrons.

Question 8

Which radiant particle cause most ionisation?

Answer 8

Alpha

Question 9

What effect does radiation have in non living things?

Answer 9

Ionisation, photographic film, scintillation.

Question 10

What affe t does radiation have in photographic film?

Answer 10

Blackens it

Question 11

What is scintillation?

Answer 11

When matierals absorb the energy and remit it as light.

Question 12

What is the activity of radiation?

Answer 12

The number of atoms that decay (are released) in one second.

Question 13

What is activity measured in?

Answer 13

Becquerel

Question 14

Does activity increase or decrease over time?

Answer 14

Decrease

Question 15

What safety precautions should be taken with radioactive materials?

Answer 15

Use tongs, store in a lead container. Point away from body, label sources, wash hands afterwards.

Question 16

What is dose equivalent?

Answer 16

Measure of the biological risk

Question 17

What is dose equivalent measured in?

Answer 17

Sieverts

Question 18

What is ionisation?

Answer 18

The addition or removal of an eke torn from an uncharged atom.

Question 19

How does a Geiger muller tube detect radiation?

Answer 19

Uses ionisation.
When radiation enters the tube it causes ionisation in the gas. This sends a pulse of electricity between the electrodes and these aw counted by the counter.

Question 20

How does photographic film detect radiation?

Answer 20

It blackens it.
Different sections of a piece of photographic paper with varying thickness are used. Type is determined by what sections are blacked (gamma blackens all) and amount by how black.

Question 21

What is half life?

Answer 21

The time taken for the activity of the source to fall by half.

Question 22

How is half life measured?

Answer 22

Take regular measurements of the activity of the source using a Geiger muller tube and counter, background radiation is then subtracted from each reading and result plotted on a graph. Graph is then used to find half life.

Question 23

What does biological effect of radiation depend on?

Answer 23

Type of absorbing tissue, type of radiation and total energy absorbed,

Question 24

Way does dose equivalent take in account?

Answer 24

Type and energy if radiation.

Question 25

Why is gamma chosen as a tracer?

Answer 25

Alpha or beta rays would be absorbed by the tissue and would not be detected outside the body.

Question 26

Why is radiation with a half life of around 6 hours used?

Answer 26

Shorter time would be too difficult to make measurements and longer would increase the amount of radiation to the body.

Question 27

What are advantages of MRI?

Answer 27

No ionisation, better for displaying soft tissue than a CT scan, nom after effects.

Question 28

What are disadvantages of MRI?

Answer 28

Any metallic objects (eg pins for fractures) will heat up. Pacemakers are affected.