Radioactivity (10) Flashcards

1
Q

At the centre of every atom is a _____________

A

Nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The nucleus of an atom, contains __________ and ___________

A

Protons and neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The nucleus of an atom makes up most of the _______ of the atom, but takes up virtually no __________

A

Weight Space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The electrons are _______________ charged and are really small

A

Negatively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The number of protons in the nucleus is called the ____________ number

A

Number of protons = atomic number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The total number of protons and neutrons in the nucleus is called the __________ number

A

Mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are isotopes

A

Atoms of the same element with different numbers of neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Isotopes are atoms of the same __________ with different numbers of ___________

A

Element

Neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

This means that different isotopes have different __________ numbers

A

Mass numbers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Usually each element only has one or two ___________ isotopes

A

Stable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

If the nucleus of an atom is unstable then it tends to be _____________. The unstable nucleus decays and emits _______________

A

Radioactive

Radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Radioactive decay is a ____________ process

A

Random

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The nuclei of unstable isotopes break down at ___________. If you have 1000 unstable nuclei, you can’t say when any of one them is going to decay, and you can’t do anything at all to make a _________ happen

A

Random

Decay

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Each nucleus decays spontaneously and is completely unaffected by physical conditions such as _________________ or ____________ bonding

A

Temperature

Chemical bonding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When a nucleus does decay it spits out one or more of the three types of radiation _________, ________ or __________

A

Alpha

Beta

Gamma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

In the process of decay, the _________ often changes into a new element

A

Nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

There is (low level) background nuclear radiation all around us all the time which come from

A

Space

Substances on earth

Living things

Human activity (nuclear explosions)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Nuclear radiation causes ______________ by bashing into atoms and knocking _____________ off them. Atoms (with no overall _________) are turned into ______ (which are __________) - hence the term ionisation (being turned into ions)

A

Ionisation

Electrons

Charge

Ions

Charged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The further the radiation can penetrate before hitting an atom and getting stopped the _________ damage it will do along the way and so t?’‘he _________ ionising it is

A

Less Less

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

____________ radiation can be detected with a Geiger-Muller detector

A

Ionising

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Alpha particles are made up of ___ protons and ___ neutrons

A

2 protons and 2 neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the features of an alpha particle

A

Big, heavy, slow moving

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the features of a beta particle

A

Quite fast, quite small

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the features of a gamma particle

A

No mass - just energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

___________ are big and heavy so they don’t _______________ far into materials and are stopped quickly

A

Alpha

Penetrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Because of their size, alpha particles are strongly ______________ which means they bash into a lot atoms and knock ______________ off them before they slow down, which creates lots of _______

A

Ionising

Electrons

Ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Because they’re electrically charged, ________ particles are deflected by electric and ____________ fields

A

Alpha

Magnetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How does emitting an alpha particle change the mass and atomic numbers of an atom

A

The mass number decreases by 4 and the atomic number decreases by 2.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

A beta particle is an ____________ which has been emitted from the nucleus of an atom when a __________ turns into a proton and an electron

A

Electron

Neutron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

When a beta particle is emitted, the number of ___________ increases by 1. So the __________ number increases by 1 but the _______ number stays the same because a neutrons is lost when it turns to a proton. (The mass number stays the same because the neutron is replaced by a proton). (E.g. instead of their being 6 protons and 6 neutrons, there are now 7 protons and 5 neutrons - still 12 overall but proton number is higher)

A

Protons

Atomic

Mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Beta particles penetrate moderately before colliding and are moderately ________________ too

A

Ionising

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Because beta particles are (negatively) ___________ they are deflected by electric and magnetic fields

A

Charged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

___________ particles can penetrate a long way into materials without being stopped

A

Gamma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Gamma rays are ___________ ionising because they tend to pass through rather than collide with _________. But eventually they hit something and do damage

A

Weakly

Atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Gamma rays have no __________, so they’re not deflected by electric or magnetic fields

A

Charge

36
Q

________ emission always happens after alpha or beta ________ . You never get just gamma rays emitted.

A

Gamma Decay

37
Q

What blocks alpha particles

A

Paper

Skin

A few centimetres of air

38
Q

What blocks beta particles

A

A thin sheet of metal

39
Q

What blocks gamma rays

A

Thick lead

Very thick concrete

40
Q

An alpha particle is made up of 2 protons and 2 neutrons and has a ____________ charge

A

Positive

41
Q

A beta particle is an electron and so has a _____________ charge

A

Negative

42
Q

A gamma ray is a wave which has _____ charge

A

No charge

43
Q

What is half-life

A

The time it takes for a radioactive material to lose half of its radioactivity / for half of the radioactive atoms present to decay

44
Q

The faster an alpha particle is travelling the _______ it will be deflected by a nucleus

A

Less

45
Q

The more positively charged a nucleus is (i.e the higher the atomic number) the ________ an alpha particle will be deflected

A

More

46
Q

The closer an alpha particle particle passes to the nucleus the ___________ it will be deflected

A

More

47
Q

Most to least dangerous radiation outside the body

A

Gamma (most)

Beta

Alpha (least)

48
Q

Most to least dangerous type of radiation inside the body

A

Alpha (most)

Beta

Gamma (least)

49
Q

Fastest to slowest type of radiation

A

Gamma (fastest - speed of light)

Beta

Alpha (slowest)

50
Q

Highest to lowest range of radiation in air

A

Gamma (most)

Beta (up to a meter)

Alpha (least)

51
Q

Which types of radiation are affected by a magnetic field

A

Alpha and Beta

52
Q

Most to least ionising type of radiation

A

Alpha (most ionising)

Beta

Gamma (least)

53
Q

Charge of alpha radiation

A

+2

54
Q

Charge of beta radiation

A

-1

55
Q

Charge of gamma radiation

A

0

56
Q

Mass of alpha radiation

A

4

57
Q

Mass of beta radiation

A

1/2000

58
Q

Mass of gamma radiation

A

0

59
Q

Most to least penetrating

A

Gamma (most)

Beta

Alpha (least)

60
Q

What is alpha radiation stopped by

A

Thin sheet of paper

61
Q

What is beta radiation stopped by

A

Thin sheet of metal

62
Q

What is gamma radiation stopped by

A

Thick sheet of lead

63
Q

How does alpha decay affect the element

A

It turns into a new element, 4 off the top number 2 off the bottom number + a helium particle with 4 as the top number and 2 as the bottom number

64
Q

How does beta decay affect the element

A

It turns into a new element top number stays the same an extra 1 onto the bottom number + an electron with 0 as the top number and -1 as the bottom

65
Q

How does gamma decay affect radiation

A

It doesn’t

66
Q

Sources of background radiation:

A

Rocks

Air (radon)

Space

Building materials

67
Q

What is ionisation

A

The adding or removing of electrons from an atom leaving the atom charged

68
Q

What is half life

A

The average time it takes for half of the radioactive nuclei to decay. E.g if something has lost 50% of its Carbon 14 then it will be 5700 years old

69
Q

Radioactivity is a __________ process - we can’t predict which atom will __________ when

A

Random

Decay

70
Q

Carbon dating is a useful way of finding the age of living things that have carbon ____ in them

A

Carbon 14

71
Q

Carbon dating is not useful for materials that are more than _________ years old or less than ______ years young

A

50000 years old 200 years young

72
Q

Explain how a smoke detector works

A

Due to alpha particles inside the smoke detector a small current is formed between 2 plates (positive and negative) When smoke gets in the way, the current stops and this triggers the alarm

73
Q

Explain how radiation is used to measure the thickness of paper

A

Above the paper is beta radiation Below the paper is a detector If the detector detects too much beta then the paper is too thin If the detector detects too little beta then the paper is too thick If the detector detects that the paper is the wrong thickness then a message will be sent and the pressure applied to the paper will be altered

74
Q

Why is gamma radiation harmless in the body

A

Because it is so not ionising that it doesn’t affect any of the body cells

75
Q

Nuclear power stations use nuclear ___________

A

Nuclear fission

76
Q

What is nuclear fission

A

The splitting of an atom, which releases energy

77
Q

In a nuclear reactor, nuclear fission is carried out in a _____________ chain reaction

A

Controlled

78
Q

How does a nuclear reaction work

A

If a slow-moving neutron gets absorbed by a uranium-235 nucleus, the nucleus can split. When it splits it releases a small number of neutrons which can go on to hit more uranium-235 nuclei which then splits and splits more and the reaction goes on and on

79
Q

When uranium-235 splits in 2 it will form ____ new daughter nuclei

A

2

80
Q

The new nuclei formed from nuclear fission is usually _________________ because they have the ‘wrong’ number of neutrons in them. This can cause huge amounts of radioactive ___________

A

Radioactive

Waste

81
Q

How does a nuclear reactor work

A

Free neutrons in the reactor start the process The reaction begins thus the temperature rises The moderator (often water) slows neutrons so that the collisions are successful Control rods absorb some neutrons to keep it controlled A gas (CO2) is pumped in to take away the heat The gas is then passes through a heat exchanger where it gives its energy to water which is then heated and turned into steam. This steam turns a turbine which turns a generator, generating electricity

82
Q

How a nuclear reactor works: Free neutrons in the reactor start the process The reaction begins meaning that the temperature __________ The moderator (often ________) slows neutrons so that the collisions are successful Control rods __________ some neutrons to keep it controlled A gas (CO2) is pumped in to take away the _________ The gas is then passes through a heat exchanger where it gives its energy to _________ which is then heated and turned into steam which turns a ___________ which turns a ___________, generating ______________

A

Rises

Water

Absorb

Heat

Water

Turbine

Generator

Electricity

83
Q

Nuclear fission equation:

A

Neutron -> Uranium which then splits in 3 - (krypton, barium and energy) this energy comes with 3 more neutrons

84
Q

How is a uranium-235 nucleus made to undergo fission

A

By surrounding it with neutrons meaning that it absorbs one

85
Q

Give one peaceful use of nuclear fission

A

Generating electricity