Nuclear Radiation

Question 1

what is an alpha particle

Answer 1

2 protons and 2 neutrons

Question 2

how far can alpha radiation travel

Answer 2

a few cm in air and is stopped by paper

Question 3

what is the most ionising type of radiation

Answer 3

alpha- safe outside the body as it can’t pass through skin, but very dangerous inside as it is so ionising

Question 4

why is a radioactive sample with short half life used as a medical tracer

Answer 4

it doesn’t last long in the body so there’s less risk of ionisation of cells due to radioactivity levels decreasing rapidly

Question 5

what affects half life

Answer 5

nothing, decay is a random process

Question 6

what is half life

Answer 6

the time taken for the original count rate of radioactive atoms of a radioactive sample to decrease by half

Question 7

why is a source of gamma radiation used as a medical tracer

Answer 7

gamma penetrates skin and tissue so can be detected outside the body
it is also least ionising

Question 8

4 natural sources of background radiation

Answer 8

radon gas
cosmic rays
food and drink (bananas)
buildings

Question 9

4 artificial sources of background radiation

Answer 9

nuclear weapons testing
nuclear power station leak
medical x rays
gamma rays in radiotherapy

Question 10

which type of radiation is least ionising

Answer 10

gamma

Question 11

what is a beta particle

Answer 11

a very fast moving electron