Ionising Radiation

Question 1

What are the characteristics of ionising radiation

Answer 1

Penetrating
Invisible to the eye
Can cause tissue damage

Question 2

What are examples of natural radiation

Answer 2

Cosmic, animals, buildings, food, people, radon gas

Question 3

What are examples of artificial radiation

Answer 3

Medical imaging, nuclear power, missiles and nuclear weapon testing

Question 4

What is a half value layer

Answer 4

The thickness of a substance which will transmit one half of the intensity of radiation incident upon it

Question 5

What is a half life

Answer 5

Time taken for half of the atoms to decay

Question 6

True or false - you can predict when an individual atom will decay

Answer 6

False - it is impossible as radioactive decay is a random process

Question 7

What are we able to predict involved with half lives

Answer 7

The fraction of the atoms that will decay over a period of time

Question 8

What is the inverse square law

Answer 8

The concentration of radiation is inversely proportional to the square of the distance - intensity reduces with distance

Question 9

What are the 3 practical principles of radiation safety

Answer 9

Time distance shielding

Question 10

What is the lead equivalence

Answer 10

The lead equivalent of an absorbing material is the thickness of lead which would absorb the same amount of radiation as the given material when exposed to radiation of the same type

Question 11

What is radon gas

Answer 11

Chemical element with the atomic number of 86 - it is a radioactive colourless and tastelesss gas

Question 12

How is radon gas formed

Answer 12

Radioactive decay of small amounts of uranium that occur naturally in rocks and soils

Question 13

What is the banana equivalent dose

Answer 13

Informal way of comparing doses of radiation to the dose received by eating a single banana

Question 14

What is radioactive decay

Answer 14

Process of an unstable atomic nucleus loses energy by emitting radiation such as alpha beta or gamma particle

Question 15

What is alpha decay

Answer 15

Spontaneous emission of an alpha particle from a nucleus

Question 16

What does alpha radiation consist of

Answer 16

Two protons and neutrons tightly bound together - a helium nucleus

Question 17

What is beta decay

Answer 17

Spontaneous emission of a fast moving particle with the mass of an electron from a nucleus

Question 18

What type of particles are produced by beta decay

Answer 18

Both negative and positive

Question 19

What is gamma decay

Answer 19

Spontaneous emission of a high energy photon with no mass from the nucleus

Question 20

Which type of radiation consists of helium-4

Answer 20

Alpha

Question 21

Which type of decay can be stopped by a aluminium plate

Answer 21

Beta

Question 22

What does beta radiation consist of

Answer 22

High energy protons or electrons

Question 23

What can stop alpha radiation

Answer 23

Sheet of paper

Question 24

What can stop gamma radiation

Answer 24

Lead

Question 25

What are the 2 classifications of action / damage resulting from radiation of cells

Answer 25

Direct and indirect

Question 26

What is indirect action / damage to tissue

Answer 26

Free radicals a produced by ionisation of water

Question 27

What is direction action / damage to tissue

Answer 27

Ionisation of macromolecules such as DNA, enzymes and proteins

Question 28

Which is the most destructive radiation

Answer 28

Alpha

Question 29

What happens in beta minus decay

Answer 29

Neutron decays to a proton and releases an electron

Question 30

What happens in beta plus decay

Answer 30

A proton decays to a neutron and releases a positron

Question 31

What is a positron

Answer 31

A positively charged electron

Question 32

How do free radicals work in indirect tissue damage

Answer 32

By transferring excess energy to other molecules and breaking chemical bonds

Question 33

What can free radicals in indirect tissue damage produce

Answer 33

Hydrogen peroxide and hydroperoxyl radical which are both highly reactive and can cause biological damage

Question 34

What are chromosomal effects from direct damage

Answer 34

Abnormal replication, cell death and the inability to pass on info

Question 35

What is the linear energy transfer

Answer 35

How much energy is transferred per unit length

Question 36

What are the two main categories of biological effects of radiation

Answer 36

Deterministic effects (tissue reactions) Stochastic effects

Question 37

What are deterministic effects - tissue reaction

Answer 37

Non cancer damaging effects that wiki definitely result from high dose radiation

Question 38

What are stochastic effects cancer and genetic effects that may develop

Question 39

What is the relationship between the severity of the effect and the threshold dose

Answer 39

Directionally - as one increases so does the other

Question 40

What are the subdivisions of tissue reactions

Answer 40

Early and late

Question 41

The ICRP uses which model

Answer 41

Liner non threshold model

Question 42

What is absorbed dose

Answer 42

Energy deposited per unit mass as is measured in joules per kg

Question 43

What symbol is used for absorbed dose

Answer 43

Gy - gray

Question 44

True or false Gy is a SI unit

Answer 44

True