Radioactivity

Question 1

Mass number

Answer 1

Total number of protons + neutrons

Question 2

Isotope

Answer 2

Atoms with the same number of protons but a different number of neutrons

Question 3

How much does the mass number and atomic number decrease in Alpha radiation

Answer 3

Mass number= -4

Atomic n umber= -2

Question 4

What is beta radiation

Answer 4

When a neutron turns into a proton and an electron is emitted

Mass number stays the same, but proton number (atomic) goes up by 1.

Question 5

What is an ion

Answer 5

Ions are charged particles

Question 6

Which radioactive source is most ionising?

Answer 6

Alpha particles

Question 7

Which radioactive source is least ionising?

Answer 7

Gamma rays

Question 8

What happens when alpha particles enter your body?

Answer 8

If alpha enters your body it can cause mutations to cells and cause cancer as it is very ionising

Question 9

How far does Alpha travel and how is it stopped?

Answer 9

Alpha travels very few cms and can be stopped by air, paper or even skin

Question 10

Rank Alpha, Beta and Gamma Lowest to highest based on penetration power

Answer 10

-Alpha
-Beta
-Gamma

Question 11

How do you stop Gamma rays?

Answer 11

With thick lead or very thick concrete

Question 12

How do you stop Beta particles?

Answer 12

By using Aluminium

Question 13

What are the uses of Radioactive particles?

Answer 13

-Alpha is used in Smoke Alarms

-Beta is used to make Aluminum or paper the right thickness

Question 14

What is background radiation

Answer 14

Radiation that is always occurring from natural or man-made sources in the surroundings.

Question 15

Radioactive decay is a ….. Process

Answer 15

Random

Question 16

Give examples of both natural and man-made sources of background radiation

Answer 16

Natural:
-Soil and air
-Cosmic rays from space (The sun)
-Living organisms

Man-made:
-Nuclear waste
-Fallout from Nuclear disasters.

Question 17

Differences between alpha and beta radiation

Answer 17

-Alpha radiation has a higher mass than Beta radiation

-Alpha radiation is more ionising than beta radiation

Question 18

Why can radon gas be harmful to humans

Answer 18

-Radon is a gas meaning it can easily be inhaled
-Radon gas contains alpha particles which when inside the body can cause both irradiation and contamination of internal organs
-Alpha is highly ionising

Question 19

Why can Thorium (Solid) be harmful to humans

Answer 19

-Thorium contains alpha particles which are highly ionising
-However it is a solid meaning it is difficult to enter the body, meaning Thorium can only cause irradiation
-Harm is only caused when inside the body as Alpha particles are stopped by a few cm of air.

Question 20

How to measure count rate from radioactive source and take into account background radiation

Answer 20

-Measure count rate without radioactive source present

-Measure the background radiation multiple times and calculate mean

-Measure the count rate with radioactive source in room
-Subtract background radiation from count rate with radioactive source.

Question 21

What type of radiation isn’t stopped by lead

Answer 21

Gamma