Radiation

Question 1

what is nuclear radiation

Answer 1

when a unstable nuclei decays it emits radiation

Question 2

why do unstable nuclei emit radiation

Answer 2

to become more stable

Question 3

name the different types of radiation

Answer 3

alpha beta gamma neutrons

Question 4

what happens when radiation moves from the nucleus

Answer 4

the overall energy of the nucleus decreases and nucleus become more stable

Question 5

what is the process of emitting radiation called

Answer 5

radioactive decay which is random

Question 6

explain alpha particles

Answer 6

alpha particles have 2 protons and 2 neutrons - like helium
don’t penetrate very far stopped by paper
carry 2+ charge and heavy/big so very ionizing

Question 7

explain beta minus decay

Answer 7

fast moving electron 
no mass
-1 charge
moderately ionising
range of a few meters in air and stopped by aluminium

Question 8

explain beta plus decay

Answer 8

fast moving positron
same mass of electron
\+1 charge
moderately ionising
small range as when hit electron they destroy each other creating gamma rays

Question 9

explain gamma rays

Answer 9

electromagnetic waves
penetrate very far stopped by lead
weakly ionising as pass through rather than colliding
highest energy
no charge

Question 10

what is ionisation

Answer 10

process by which an atom loses an electron due to radiation the number of electrons change to net plus charge

Question 11

What is background radiation

Answer 11

the radiation existing behind us

Question 12

what are the origins of radiation from natural sources

Answer 12

• radon gas from rocks
• cosmic rays from sun
• carbon-14

Question 13

what are man-made sources of radiation

Answer 13

• medical sources
• nuclear waste
• nuclear explosions

Question 14

what is radon gas from rocks and soil really mean

Answer 14

radioactive elements such as uranium occur in rocks and decay into radon gas which is dangerous if inhaled

Question 15

what is cosmic rays from space really mean

Answer 15

sun emits protons which collide with molecules in air and produce gamma rays

Question 16

what is irradiation

Answer 16

objects being exposed to radiation - not making it radioactive

Question 17

how can you reduce irradiation

Answer 17

use photographic film badge to monitor levels of radiation

stay behind barriers and rooms to reduce irradiation

Question 18

what is contamination

Answer 18

when radioactive elements get onto an object which then decay and release radiation which cause harm

Question 19

how can u reduce contamination

Answer 19

use gloves and tongs and protective suits

Question 20

how can radiation damage cells

Answer 20

enter living cells and ionise atoms leading to tissue damage

Question 21

what does lower dose of radiation cause

Answer 21

minor damage cause a rise in mutant cells dividing uncontrollably causing cancer

Question 22

what does higher dose of radiation cause

Answer 22

killing cells causing radiation sickness

Question 23

what are most dangerous radioactive elements outside of body

Answer 23

alpha and gamma radiation because they can penetrate body and damage delicate organs

Question 24

what is the most dangerous inside body

Answer 24

alpha radiation because strongly ionising and damage localised meaning alpha radiation can cause contamination

Question 25

what two equipment can you use to detect radiation

Answer 25

• photographic film

- Geiger-muller tube

Question 26

how does the photographic film badge work

Answer 26

• when radiation is absorbed the film badge gets darker
• used to monitor radiation for people who work closely with radiation
• film badge contains different materials to identify different types of radiation exposed to

Question 27

how does the geiger muller tube work

Answer 27

each time it absorbs radiation it transmits electrical impulse making a clicking sound and displaying count rate
- greater clicks more radiation so if muller tube is closer to source of radiation higher count rate

Question 28

what happens during beta minus decay

1. what acc is beta minus decay
2. what happens during beta minus decay
3. what happens to the mass number
4. what happens to atomic number

Answer 28

1. high energy electrons emitted from nucleus
2. neutron changes to proton and electron
3. mass number doesn’t change as lost neutron but gained proton
4. atomic number increases and one more proton

Question 29

what happens in beta plus decay

1. what acc is beta plus decay
2. what happens during beta plus decay
3. what happens to the mass number
4. what happens to atomic number

Answer 29

1. high energy positrons emitted from nucleus
2. proton changes into neutron and positron
3. mass number doesn’t change as proton change into neutron
4. atomic number decrease as one less proton

Question 30

what happens during alpha decay

1. what acc is alpha decay
2. what happens during alpha decay
3. what happens to the mass number
4. what happens to atomic number

Answer 30

1. strongly ionising radioactive element that is similar to a helium nucleus
2. lose two protons and two neutrons
3. decreases by 4
4. decreases by 2

Question 31

what happens during gamma decay

Answer 31

an atom gets rid of excess energy by emitting gamma radiation to reach a more stable state there is no change in mass and atomic number