Topic 4- Hazards and uses of radioactive emissions and background radiation

Question 1

Give 4 sources of background radiation

Answer 1

Rocks
Cosmic rays from space
Nuclear weapons testing
Nuclear accidents

Question 2

How should background radiation be dealt with in calculations?

Answer 2

The background count should be subtracted from any readings before calculations are attempted

Question 3

What is the unit used to measure radiation dosage?

Answer 3

Sieverts

Question 4

How many millisieverts equal 1 sievert?

Answer 4

1000 milliesieverts= 1 sievert

Question 5

Why might the radiation dosage that different people experience differ?

Answer 5

Some occupations involve working with radiation
Background radiation differs with no location due to things such as the locality of nuclear power stations or radiation related testing

Question 6

What factor determines how dangerous a particular radioactive isotope is?

Answer 6

the half-life of the isotope

Question 7

Why are isotopes with long half-lives particularly harmful?

Answer 7

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

Question 8

State two uses of nuclear radiation in the field of medicine

Answer 8

Examining internal organs
Controlling and destroying unwanted tissues (Cancer treatment)

Question 9

How is radiation used in sterilisation

Answer 9

Gamma emitters are used to kill bacteria/parasites on equipment

Question 10

Explain the process of radiotherapy

Answer 10

Gamma emitters direct gamma rays at cancerous cells
The cancerous cells absorb the radiation and are killed

Question 11

How are medical tracers chosen?

Answer 11

They should have a short half life and decay into a stable isotope which can be excreted
They should only release gamma radiation since it is weakly ionising and can easily pass through body tissue without damaging it