Topic 4 Isotopes And Nuclear Radiation Flashcards

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1
Q

What are isotopes

A

Different forms of the same element
Have the same number of protons and electrons but a different number of protons

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2
Q

What happens to unstable isotopes

A

Tend to decay into other elements and give out radiation as they try to become more stable
This process is called radioactive decay

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3
Q

Why might isotopes release neutrons when they decay

A

To rebalance their atomic and mass numbers

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4
Q

What is ionising radiation

A

Radiation that knocks electrons off atoms creating positive ions

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5
Q

What is the ionising power of a radiation source

A

How Easily it can knock electrons off

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6
Q

What type of radiation is the least penetrating

A

Alpha particles
Don’t penetrate very far and are stopped quickly
Can only travel a few cm in the air and are absorbed by a sheet of paper

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7
Q

Why are are alpha particles strongly ionising

A

Because of their size

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8
Q

How ionising are beta particles

A

Moderately ionising
Penetrate moderately far into materials before colliding and and range in air a few meters
They are absorbed by a sheet of aluminium around 5mm

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9
Q

What is the mass of beta particles

A

Negligible 

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10
Q

What happens for every beta particle that is emitted

A

A neutron in the nucleus has turned into a proton

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11
Q

What are gamma rays

A

Wave of electromagnetic radiation released by the nucleus

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12
Q

How penetrating are gamma rays

A

Penetrate far into materials without being stopped and will travel a long distance through the air

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13
Q

Why are gamma rays not ionising

A

Because they tend to pass through rather than collide with atoms

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14
Q

What can gamma rays be absorbed by

A

Thick sheets of lead or metres of concrete

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15
Q

What is alpha radiation used for

A

Smoke detectors
Ionises particles in the air causing current to flow
If smoke is in the air it binds to the ions meaning the current stops and the alarm sounds

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16
Q

What are beta emitters used for

A

To test the thickness of the sheets of metal as the particles are not immediately absorbed but the material like alpha and wouldn’t penetrate as far as gamma

17
Q

What are the types of ionising radiation elevated by radioactive substances

A

Alpha
Beta
Gamma

18
Q

What are alpha particles

A

Helium nuclei

19
Q

What is an alpha particle made up of

A

2 neutrons and 2 protons

20
Q

What is alpha radiation

A

When alpha particles are emitted from a nucleus

21
Q

How far can alpha particles travel

A

Only a few cm in air and are stopped by paper
This is because they are the least penetrating

22
Q

Why are alpha particles strongly ionising

A

Because of their size

23
Q

What are beta particles

A

High speed electrons that have virtually no mass and a charge of -1

24
Q

How ionising are beta particles

A

Moderately ionising

25
Q

How penetrating are beta particles

A

Can go a few meters in air and are absorbed by a sheet of aluminium around 5mm

26
Q

What happens when every beta particle is emitted

A

A neutron in the nucleus turns into a proton

27
Q

What are gamma rays

A

Waves of electromagnetic radiation released by the nucleus

28
Q

How penetrating are gamma rays

A

Penetrate far into materials without being stopped and can travel long distances in the air
They are absorbed by thick sheets of lead or meters of concrete

29
Q

Why are gamma rays weakly ionising

A

Tend to pass through rather than collide with atoms but eventually hit something and do damage

30
Q

What is alpha radiation used in

A

Used in smoke detectors as it ionises air particles causing current to flow

31
Q

How does the smoke detector work

A

If smoke in the air then it brings to the ions meaning the current stops and the alarm sounds

32
Q

What are beta emitters used to test

A

Thickness of sheets of metal as they are not immediately absorbed like alpha radiation but also do not penetrate as far as gamma rays