radioactivity,nuclear equations, half life, contamination

Question 1

name a radioactive isotope

Answer 1

carbon 14 14c6

Question 2

some isotopes have an unstable…

Answer 2

some isotopes have an unstable nucleus, to become stable the nucleus gives out radiation this radiation is called radioactive decay

Question 3

radioactive decay is a completely random process

Answer 3

scientists cannot predict when a nucleus will decay

Question 4

what is the definition of activity

Answer 4

-the rate at which a source of unstable nuclei decay

Question 5

activity is measured in:

Answer 5

becquerels- 1 bequerels is one decay per second

Question 6

to measure activity

Answer 6

use a geiger muller counter

Question 7

what is the count rate

Answer 7

the count rate is the number of decays recorded each second by a detector

Question 8

4 different types of radiation that can be given out by an unstable nucleus

Answer 8

• alpha particle
• gamma particle
• beta particle

Question 9

alpha particles is the same as the nucleus of which atom

Answer 9

-helium

alpha particles have 2 neutrons and 2 protons

Question 10

what is a beta particle

Answer 10

a beta particle is an electron which is ejected from the nucleus at a very high speed
the beta particle is formed inside a nucleus when a neutron changes to into a proton and a electron

Question 11

gamma rays

Answer 11

gamma rays are not particles they are a type of electromagnetic radiation from the nucleus

Question 12

neutron

Answer 12

sometimes given out by a nucleus

Question 13

alpha particles range in air:

Answer 13

alpha particles are large they can travel around 5cm in air before they collide with air particles and stop

Question 14

beta particles range in air

Answer 14

can travel further, can travel 15 cm in air before stopping

Question 15

gamma radiation range in air

Answer 15

gamma radiation can travel several metres in air before stopping

Question 16

alpha particles penetrating power

Answer 16

relatively easy to stop

can be stopped by a single sheet of paper

Question 17

beta particles penetrating power

Answer 17

harder to stop

can be stopped by a few millimeters of aluminium

Question 18

gamma radiation penetrating power

Answer 18

gamma radiation is stopped by several centimeters of lead

Question 19

what is ionising power

Answer 19

when radiation collides with atoms, that causes an atom to lose electrons and form ions

Question 20

alpha particles ionising power

Answer 20

alpha particles are very strongly ionising

Question 21

beta particles ionising power

Answer 21

quite strongly ionising but not as much as alpha particles

Question 22

gamma radiation ionising power

Answer 22

weakly ionising.