9A.1 Nuclear Radiation

Question 1

what is background radiation

Answer 1

low levels of radiation from environmental sources, always present around us

Question 2

what is half of the background radiation made from

Answer 2

radioactive gases which are in our atmosphere, particularly radon

Question 3

how is radon produced

Answer 3

produced by the decay of a uranium ore which is present in certain rocks (specially granite) so radon is found in more quantities in certain places

Question 4

how do we measure the background radiation

Answer 4

by using a Geiger-Muller tube and counter and let it stay on for about 30 minutes then divide the number of counts by the time in seconds to get the activity in Bq, we should repeat this multiple times and find the average

Question 5

what do we have to leave the Geiger-Muller tube on for loner times

Answer 5

because radioactive decay is a very spontaneous and random process so you might then get a very low or very radioactivity thats why its left for 30 mins or more

Question 6

how do we get the correct counts for the activity of an radioactive source under test

Answer 6

use a Geiger-Muller tube and find activity the minus the activity from the background radiation

Question 7

what is a decay

Answer 7

a process in which the nucleus structure is changed usually accompanied by the emission of a particle

Question 8

what happens to the radiation particles emitted from nuclear decay

Answer 8

it will the nucleus with a kinetic energy, ionizing particles in its path, losing some energy at each ionization, and when the kinetic energy is completely transferred, the radiation particle stops and is absorbed by the substance it is in at the moment

Question 9

what are the 3 types of nuclear decay

Answer 9

1. Alpha
2. Beta
3. Gamma

Question 10

how can we measure the penetrating power of alpha, gamma, and beta radiation

Answer 10

by using a G-M tube and the source of radiation, then place an absorber sheets between the G-M tube and the source, the sheets will progressively increase in density and then measure the average count rate for each of the sources and very density

Question 11

how can you reduce the risk of radioactivity when doing any experiments

Answer 11

handle the radioactive source with a long pair of tongs and don’t point the open end of the source at any part of the body, and once done with the source return it

Question 12

what is an alpha particle

Answer 12

it is a particle composed of two protons, two neutrons same a as a helium nucleus

Question 13

what are the properties of alpha particles

Answer 13

it is a very large particle with high charge of +2e and has very strong ionizing power but not a strong penetrating power as it can be stopped by air of skin

Question 14

what is an example of an alpha decay equation

Answer 14

page 135

Question 15

what is a beta particle

Answer 15

an electron emitted at high speeds from the nucleus when a neutron decays into a proton.

Question 16

what are the properties of beta particles

Answer 16

very small, with a negative charge of e, and is less ionizing than an alpha particle but more penetrating than it as its stopped by an aluminium sheet

Question 17

what is an example of beta decay

Answer 17

page 136

Question 18

what gamma rays

Answer 18

high energy, high frequency, electromagnetic radiation, emitted from nuclear gamma decay

Question 19

what are the properties of gamma rays

Answer 19

they have no mass no charge they barely ionize any particles but they are very penetrating as they are never absorbed but when reduced a safe level we would call them absorbed and that only happens with several cm of lead of meters of concrete

Question 20

what is an example of gamma decay

Answer 20

page 136

Question 21

what does gamma radiation do to the nucleus

Answer 21

it doesn’t change the composition of the nucleus it just makes the nucleus drop down an energy level

Question 22

when does gamma decay occur

Answer 22

usually straight after alpha, or beta decay as it leaves the nucleus at an excited state

Question 23

how can we investigate the lead absorption of gamma radiation

Answer 23

place a G-M tube across a radioactive source of alpha and gamma radiation place a sheet of paper to absorb all the alpha radiation and from their keeping the G-M tube in place add different thicknesses of lead over a period of time and measure the correct counted rate at each thickness of lead from their draw a graph to show that the intensity of radiation is proportional to e^-ux x=thickness

Question 24

what is the risk of different radiation inside the body

Answer 24

alpha - very dangerous can cause cancer and radiation poisoning - high ionization

beta - moderate danger - should minimize exposure - mid ionization

Gamma - minimal danger - cancer danger from long term exposure - no ionization

Question 25

what is the risk of different radiation outside the body

Answer 25

alpha - no danger absorbed by dead skin cells -low penetration

beta - moderate danger - should minimize exposure - mild ionization and penetration

Gamma - minimal danger - cancer danger from long term exposure - low ionization and high pentation

Question 26

what is it danger to be exposed to radioactive particles

Answer 26

it can kill our cell or mutated them to form cancer