Radiation

Question 1

What is an isotope

Answer 1

Is an atom of the same element with the same number of protons but different number of neutrons

Question 2

What is radiation

Answer 2

Isotopes can become unstable and emit radiation from their nucleus

Question 3

Give the 4 main types of radiation

Answer 3

Alpha
Beta
Gamma
Neutron

Question 4

What does it mean by a random process

Answer 4

We cannot tell when a single nucleus will decay

Question 5

What is background radiation

Answer 5

The natural level of radiation that we find in air

Question 6

Give some examples of background radiation

Answer 6

Radon gas (the air around us)
Buildings, rocks and soil
Cosmic rays
Medical equipment
Food and drink

Question 7

Give the name of a detector that measure radiation levels

Answer 7

Geiger - Muller tube

Question 8

What is an ion

Answer 8

An atom or a molecule with a charge

It can either be +ve or -ve

Question 9

What is Ionisation

Answer 9

Is the REMOVAL or ADDITION of an ELECTRON to create an ION. Electrons can be lost from an atom because of ionising radiation

Question 10

What is alpha radiation

Answer 10

Helium nucleus
2 protons and 2 neutrons
Heavy
Stopped by paper
10cm range in air

Question 11

What is Beta

Answer 11

An electron
-1 charge
Stopped by a few mm of aluminium
1m range in air

Question 12

What is Gamma

Answer 12

Electromagnetic wave
High energy
0 charge
Km’s range in air

Question 13

What is neutron radiation

Answer 13

Neutrons are edited by radioactive material. They have roughly the same mass as a proton but have no electric charge (they are neutral)

As they are not electrically charged, neutrons emitted by a nucleus do not cause ionisation. They can be absorbed b other nuclei

Question 14

What are the units we use for a radioactive source

Answer 14

Bq

Question 15

What is a half life

Answer 15

The amount f time taken for half of the NUCLEI in a SAMPLE to decay.
The activity of a radioactive sample decreases over time

Question 16

How do you find the half life on a graph

Answer 16

Calculated by halving the activity and checking the corresponding time, we do this more than once and the average

Question 17

Give the dangers of alpha radiation

Answer 17

The most ionising radiation

Can only cause ham if it’s inside the body

Question 18

Give the dangers of Beta and Gamma radiation

Answer 18

They have much less chance of ionising your cells. However they are able to penetrate the skin

Question 19

What is irradiation

Answer 19

Is where someone is exposed to radiation

Question 20

What is contamination

Answer 20

Is where we absorb radioactive material such as dust. This then emits radiation

Question 21

Give 3 uses of radiation in the Industry

Answer 21

Gamma radiography
Gauging
Pipe tracers

Question 22

What is radiography

Answer 22

Used to see through an object without destroying it

Certain materials are better at absorbing gamma rays ( allowing us to create an image of the object)

e.g X-rays at airports

Question 23

What is Gauging

Answer 23

Can be used to measure the amount of material inside a tube or a container

It can also be used to determine the type or thickness e.g when pressing sheet metal

Question 24

What are pipe tracers

Answer 24

Can be used to find a leak in the pipes
Radioactive gamma with a sort half life is ut in a liquid and run through a pipe.
When the amount of radiation in the surface changes, you have found a leak

Question 25

What are medical tracers

Answer 25

Radioactive tracers which are used to investigate a patients body without the need for surgery. Gamma and Beta emitters are used as they can penetrate the skin whereas alpha can't. A small amount of radioactive material is put into the patients body, a detector can then detect any Gamma or Beta rays that pass out the body

Question 26

What is radiotherapy

Answer 26

Gamma rays are focused on the tutor to kill the cells. This is done by using a wide beam of gamma rays but rotating it around keeping the tutor at the centre.

Question 27

What is sterilisation

Answer 27

Gamma rays pass through the packaging and inactivate viruses and kill bacteria. S long as the equipment remains in a sealed package, it will remain sterile.

Question 28

Explain carbon dating

Answer 28

All living things absorb and emit radiation and so maintain a constant level while they are living. When they die, this level is no longer constant. The Carbon-14 isotope that was present at death decays over time. Because we know the half life of Carbon-14, we can measure the radioactivity of a fossil/skeleton and estimate how long it has been dead