P5

Question 1

What is an alpha particle?

Answer 1

A helium nucleus

Question 2

What is a beta particle?

Answer 2

A high energy electron

Question 3

What is gamma radiation?

Answer 3

An electromagnetic wave

Question 4

What are the properties of alpha particles?

Answer 4

High ionization
Low penetration
Stopped by paper

Question 5

What are the properties of beta particles?

Answer 5

Medium ionization
Medium/low penetration
Stopped by aluminium

Question 6

What are the properties of gamma radiation?

Answer 6

Low ionization
High penetration
Stopped by lead

Question 7

How did Rutherford disprove the plum pudding model?

Answer 7

He sent alpha particles (which are positive) into a shin sheet of gold, and although most particles went through without changing path, some particles were rebounded hugely. This proved that there was a positively charged center of mass in the atom (the nucleus)

Question 8

What is the size difference between the diameter of a atom and a nucleus?

Answer 8

An atom is roughly 100,000 times larger than a nucleus

Question 9

When 1 beta particle is emitted, what is the effect on the atomic number?

Answer 9

It will increase 1

Question 10

When 1 beta particle is emitted, what is the effect on the atomic mass?

Answer 10

There is no effect

Question 11

When 1 neutron is emitted, what is the effect on the atomic number?

Answer 11

There is no effect

Question 12

When 1 neutron is emitted, what is the effect on the atomic mass?

Answer 12

It will decrease by 1

Question 13

What is an isotope?

Answer 13

An element with a different number of neutrons, but the same amount of protons and electrons

Question 14

What is the half-life of a source?

Answer 14

The time it takes for activity to halve from its original value

Question 15

What is irradiation?

Answer 15

When an object is exposed to radiation

Question 16

What is contamination?

Answer 16

When a radioactive source is in or on an object, therefore the object becomes a source

Question 17

What can high doses of radiation do?

Answer 17

Kill cells completely

Question 18

What can low doses of radiation do?

Answer 18

Cause cell mutations which can lead to cancer

Question 19

How damaging is gamma waves outside the body?

Answer 19

Gamma are dangerous outside the body as they can penetrate very far into the body and get to delicate organs

Question 20

How damaging is gamma waves inside the body?

Answer 20

Gamma rays are not dangerous inside the body, as due to their high penetration, most of the radiation just passes through without doing any damage

Question 21

How damaging is alpha particles outside the body?

Answer 21

Alpha particles are not dangerous outside the body, as due to their low penetration, they cannot penetrate the skin, preventing them from causing any harm

Question 22

How damaging is alpha particles inside the body?

Answer 22

Alpha particles are very dangerous inside the body, as they do all their damage in a very localised area, likely causing cell destruction

Question 23

How damaging is beta particles outside the body?

Answer 23

Beta particles are fairly dangerous outside the body, as they can penetrate the body and therefore cause damage, just not as much as gamma waves

Question 24

How damaging is beta particles inside the body?

Answer 24

Beta particles are less damaging than alpha inside the body, as they do their damage over a wider area, and some particles pass out completely

Question 25

What do tracers do?

Answer 25

They see if parts of the body are working

Question 26

What radiation do tracers use and why?

Answer 26

They use gamma sources with a short half-life, as gamma can penetrate through the body and be detected by the sensors without causing much damage

Question 27

How are tracers taken into the body?

Answer 27

They are injected or ingested

Question 28

How do we treat cancer externally?

Answer 28

A beam of gamma rays are fired at the tumour, in the hope it will kill the cancer cells

Question 29

How do we treat cancer internally?

Answer 29

Implants containing beta or alpha emitters are placed in or next to a tumour, in the hope they will kill the cancer cells

Question 30

Why do we use beta or alpha emitters in implants?

Answer 30

They can damage the cancer cells, however have a short range so healthy cell damage is limited

Question 31

What do we have to do to long half-life implants?

Answer 31

We must remove them to stop them killing more healthy cells after the cancerous cells have been killed

Question 32

What do we have to do to short half-life implants?

Answer 32

Nothing- we can leave them in there as their activity will fade away quick enough so as to not cause further healthy cell damage

Question 33

What is activity measured in?

Answer 33

Bq

Question 34

Describe the process of nuclear fission

Answer 34

1) A large unstable nucleus absorbs a neutron, causing it to split into 2 smaller nuclei 2) This change gives out a lot of energy 3) Each time a nucleus splits, some neutrons are also spat out 4) Each of these neutrons has the ability to cause another nuclei split and so on and so on 5) This is called a chain reaction

Question 35

What do 2 hydrogen nuclei form when fused together?

Answer 35

A helium nucleus

Question 36

Where is the energy produced from in fusion?

Answer 36

The change in mass between the original and new nucleus is converted into energy and carried away by radiation

Question 37

What are the pros of nuclear energy?

Answer 37

``` No greenhouse gases Low operating costs Reliable Efficient Possibly renewable in the future ```

Question 38

What are the cons of nuclear energy?

Answer 38

``` Environmental impact Difficult waste disposal Nuclear accident risk Expensive to set up Target for militants Right now, non-renewable ```