isotopes and radioactivity

Question 1

isotope

Answer 1

atoms with the same number of protons and a diffferent number of neutrons

Question 2

unstable isotope

Answer 2

when the proton to neutron ratio is too disproportionate

Question 3

how to know if an isotope is unstable

Answer 3

unstable isotopes emit energy which can be detected

Question 4

beta minus decay

Answer 4

a neutron changes to a proton and creates a beta minus particle
beta minus particle also emits gamma radiation as the nucleus has to rearrange itself

Question 5

beta plus decay

Answer 5

proton changes to a neutron and creates a beta plus particle (also known as a positron)

Question 6

gamma emmission

Answer 6

when the nucleus rearranges itself and emits gamma radiation

Question 7

describe an alpha emission

Answer 7

alpha particle is created which removes 2 protons and neutrons from the isotope

Question 8

proton emission

Answer 8

when a proton gets kicked out of the nucleus

Question 9

neutron emission

Answer 9

when a neutron gets kicked out of the nucleus

Question 10

Material that stops alpha

Answer 10

Paper or a human hand

Question 11

material that stops beta emissions

Answer 11

aluminium

Question 12

material that stops gamma emissions

Answer 12

lead

Question 13

contamination

Answer 13

when radioactive material is on you

Question 14

irradiation

Answer 14

when you are exposed to radioactive emssions

Question 15

most - least ionising radiations

Answer 15

alpha - beta - gamma

Question 16

most - least penetrating radiations

Answer 16

gamma - beta - alpha

Question 17

mass and charge of gamma particle

Answer 17

no mass, no charge

Question 18

mass and charge of beta minus particle

Answer 18

relative mass of 0
charge of -1

Question 19

charge of positron

Answer 19

+1

Question 20

explain the dangers of irradiation and contamination
(4 marks)

Answer 20

• irradiation is when you are exposed to radioactive emissions
• contamination is when you have radioactive material on you
• it is more dangerous if you are contaminated as you carry radioactive material e.g. gamma radiation can cause cancer which damages cells
• if you are contaminated you are constantly irradiated

Question 21

describe the dangers of ionising radiation and discuss the precautions which could be taken to limit the dose of radiation received by a person
(6 marks)

Answer 21

• ionising radiations can damage cells
• geiger muller tubes are used to detect radioactivity by measuring the background radiation and checking if there is a large change when the tube is pointed at you
• photographic film is used to detect how much radiation you are exposed to the darker it gets
• tongs prevent contamination as you do not have to touch the radioactive material
• gloves can also be worn to prevent contamination
• standing behind concrete walls will prevent irradiation as the wall will absorb the radiations