Nuclear Radiation

Question 1

what is an isotope

Answer 1

a different form of the same element with different numbers of neutrons

Question 2

what is radioactive decay

Answer 2

when isotopes decay into other elements and give out radiation as they try to become more stable

Question 3

atoms are neutral which means…

Answer 3

they have no overall charge

Question 4

what can happen when ionising radiation interacts with an atom

Answer 4

it can cause the atom to lose an electron, making the atom positively charged

Question 5

what are the three types of ionising radiation

Answer 5

alpha, beta, gamma

Question 6

what type of nuclei are alpha particles

Answer 6

helium nuclei, they have two protons and two neutrons

Question 7

what is the charge of an alpha particle

Answer 7

+2

Question 8

what can alpha particles be stopped by

Answer 8

a few cm of air, a sheet of paper

Question 9

what is a use of alpha particles

Answer 9

they can be used in smoke detectors

Question 10

a beta particle is…

Answer 10

a fast moving electron released by the nucleus when a neutron turns into a proton

Question 11

what charge do beta particles have

Answer 11

-1

Question 12

beta particles can be stopped by

Answer 12

a few metres of air/ aluminium

Question 13

beta particles can be used to

Answer 13

test the thickness of paper

Question 14

what are gamma rays

Answer 14

EM waves with a short wavelength

Question 15

do gamma rays have a high or low frequency

Answer 15

high frequency

Question 16

what is the charge of a gamma ray

Answer 16

they have no charge

Question 17

gamma rays are weakly ionising because

Answer 17

they pass through materials rather than colliding with atoms

Question 18

what can gamma rays be absorbed by

Answer 18

a thick sheet of lead or metres of concrete

Question 19

what is the definition of half life

Answer 19

the half life is the average time taken for the number of radioactive nuclei in an isotope to halve

Question 20

what is the equation to determine the activity of a source

Answer 20

A= N/t activity= number of disintegrations/ time

Question 21

what is activity measured in

Answer 21

becquerels

Question 22

another use of gamma rays is to

Answer 22

sterilise food

Question 23

why can ionising radiation be dangerous

Answer 23

it can enter cells and cause ionisation or cancer

Question 24

low doses of ionising radiation damage living cells by…

Answer 24

causing mutations in DNA

Question 25

what particles are most dangerous outside the body

Answer 25

beta and gamma

Question 26

what particles are most dangerous inside the body

Answer 26

alpha

Question 27

what are some sources of background radiation

Answer 27

the air, certain foods, rocks, the sun, nuclear fallout, medical procedures etc

Question 28

the equation for absorbed dose is

Answer 28

D=E/m absorbed dose= energy/ mass

Question 29

what is the unit for absorbed dose

Answer 29

gray, Gy

Question 30

what is the equation for equivalent dose

Answer 30

H=Dw equivalent dose= absorbed dose* weighting factory

Question 31

how is the energy in a uranium or plutonium atom released

Answer 31

through nuclear fission

Question 32

chain reactions happen when

Answer 32

neutrons released by fission reactions have a lot of energy and will cause more fission reactions to occur.

Question 33

fission energy is used to fuel

Answer 33

nuclear power stations

Question 34

what is the energy from fission reactions converted to

Answer 34

heat energy

Question 35

what is nuclear fusion

Answer 35

it is the opposite of nuclear fission.
two light nuclei collide at a high speed and fuse to create a larger heavier nucleus.

Question 36

fusion only happens at

Answer 36

extremely high pressures and temperatures

Question 37

why is plasma hard to contain in a fusion reactor

Answer 37

its too hot to come into contact with any material