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Question 1

2 ways that an atoms electron arrangement can be changed

Answer 1

Absorbing EM radiation
Emitting EM radiation

Question 2

Explain how an atoms electron arrangement changes when it absorbs em radiation

Answer 2

Electrons move further away from nucleus
Higher energy level

Question 3

Explain how an atoms electron arrangement changes when it emits em radiation

Answer 3

Electrons move closer to nucleus
Move to lower energy level

Question 4

Why do unstable nuclei give out radiation

Answer 4

They undergo decay to become more stable
As they release radiation their stability increases

Question 5

What is radioactive decay

Answer 5

Process in which an unstable nucleus gives out radiation to become more stable

Question 6

State 4 types of nuclear radiation

Answer 6

Alpha
Beta
Gamma
Neutrons

Question 7

Give equation for an alpha particle

Answer 7

a42

Question 8

Range of alpha particle thru air

Answer 8

Few centimetres

Question 9

What will stop beta radiation from passing thru a point

Answer 9

Thin sheet of aluminium
Several meters of air

Question 10

Equation for beta particle

Answer 10

B0-1

Question 11

What will stop gamma radiation from passing thru a point

Answer 11

Several cm of lead
Few metres of concrete

Question 12

Equation for gamma radiation

Answer 12

Y00 (em wave)

Question 13

Radiation types from most ionising to least

Answer 13

Alpha
Beta
Gamma

Question 14

What changes to mass or charge occur due to emission of a gamma ray

Answer 14

Both mass and charge remain unchanged

Question 15

Describe the nature of radioactive decay

Answer 15

Random
Which nuclei decays and when it does is determined only by chance
It is impossible to predict which nuclei will decay and when

Question 16

Describe half life of radioactive isotope

Answer 16

Time taken for number of unstable nuclei in a substance to halve
Time taken for the count rate from a sample to call to half its initial level

Question 17

Radiation types in order of most penetrating to least

Answer 17

Gamma, beta, alpha

Question 18

What is radioactive contamination

Answer 18

Presence of unwanted radioactive nuclei on other materials

Question 19

What is irradiation

Answer 19

Process of exposing a material to nuclear radiation
The material does not become radioactive

Question 20

Give 3 practices applications of radioactive materials

Answer 20

Medical tracers
Radiotherapy
Smoke alarms

Question 21

What kind of radiation is used in smoke alarms

Answer 21

Alpha

Question 22

How do smoke alarms work

Answer 22

Alpha radiation emitted into air, reaching a detector and completing the circuit
If smoke is present, it blocks alphas radiation so it doesn’t reach the detector and the circuit is broken
Causing an alarm to sound

Question 23

Give a use of beta emitters

Answer 23

Thickness monitoring of paper

Question 24

How does thickness monitoring work

Answer 24

A source and receiver are placed on either side of the sheet
If there is a drop in rise in the no. of particles detected, the thickness has changed and needs adjusting

Question 25

Why are isotopes with long half lives particularly harmful

Answer 25

They remain radioactive for much longer periods of time Must be stored in specific ways to avoid humans and the environment from being exposed to radiation for too long

Question 26

State 2 uses of nuclear radiation in the field of medicine

Answer 26

Examining internal organs Controlling and destroying unwanted tissue

Question 27

How is radiation used in sterilisation

Answer 27

Gamma emitters are used to kill bacteria/parasites on equipment

Question 28

What kind of radiation is used for radiotherapy

Answer 28

Gamma

Question 29

Explain the process of radiotherapy

Answer 29

Gamma emitters direct gamma rays onto specific areas with cancerous cells The cells absorb the radiation and die

Question 30

What are the risks of ionising radiation to ppl

Answer 30

It can damage living cells, causing them to die or mutate and become cancerous

Question 31

What is nuclear fusion

Answer 31

Joining of 2 light nuclei to produce a heavier nuclei and release energy

Question 32

Name 2 isotopes of hydrogen which are commonly used in nuclear fusion

Answer 32

Deuterium and tritium

Question 33

Which releases more energy, nuclear fission or fusion

Answer 33

Fusion

Question 34

Explain the difficulty of generating energy through nuclear fusion

Answer 34

Fusion requires very high temps which in itself required large quantities of energy and also requires casing which can withstand them

Question 35

What can mass be converted into

Answer 35

Energy

Question 36

What is nuclear fission

Answer 36

Splitting of large unstable nuclei to form smaller more stable nuclei (emission of spare neutrons)

Question 37

What usually needs to happen to induced fission

Answer 37

Unstable nuclei must absorb a neutron Spontaneous fission (where no neutron absorption occurs) is rare

Question 38

Alongside 2 smaller nuclei, what else is emitted in a fission reaction

Answer 38

2 or 3 neturons Gamma rays Energy

Question 39

What takes place during a chain reaction in a nuclear reactor

Answer 39

Unstable nuclei absorbs a neutron Nucleus undergoes fission and releases 2 or 3 further neturons These induce more fission, which results in a chain reaction

Question 40

Which radiation is most damaging inside and outside the body

Answer 40

Inside- alpha Outside- gamma