Background radiation

Question 1

what is background radiation?

Answer 1

the low levels of (ionising) radiation that are always present around us

it can be natural or man-made

Question 2

name seven sources of radiation

Answer 2

natural:
radon gas (50%)

ground/buildings (14%)

cosmic rays from space (10%)

man-made:
medical (14%)

nuclear power (0.3%)

food and drink (11.5%)

other (0.2%)

Question 3

percentages that these types of radiation account for:

a) radon
b) medical
c) nuclear power

Answer 3

a) 50%
b) 14%
c) 0.3%

Question 4

radon (3)

Answer 4

a radioactive gas that is produced when uranium in rocks decays

the radon can build up in houses and other buildings

the amount of radon gas varies from place to place, because it depends on the type of rock in the area

Question 5

Give two examples of background radiation that are:

a) naturally occurring [2]
b) from human activities [2[

Answer 5

a) cosmic rays
radioactivity from the ground
radon gas

b) nuclear power
medical
food and drink

Question 6

Explain why radon is more dangerous inside the body than outside the body [3]

Answer 6

radon gas emits alpha particles which are highly ionising and cause damage inside the body

they have too small a range in air to reach the body, so will not cause harm outside it