Atomic physics

Question 1

Describe the structure of an atom

Answer 1

Positively charged nucleus surrounded by negatively charged electrons

Question 2

Describe how the scattering of α-particles by thin metal foils provides evidence for the nuclear atom

Answer 2

1. Majority of them go straight through
2. Some are slightly deflected
3. Very few are deflected straight back

Question 3

Which experiment investigates the scattering of α-particles?

Answer 3

Rutherford’s gold foil experiment

Question 4

What is the nucleon number also referred to as?

Answer 4

Mass number

Question 5

What is the proton number also referred to as?

Answer 5

Atomic number

Question 6

What is meant by the term nuclide?

Answer 6

A nucleus with a specific combination of protons and neutrons

Question 7

What is an isotope?

Answer 7

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

Question 8

What is nuclear fission?

Answer 8

The splitting of nuclei to release energy

Question 9

What is nuclear fusion?

Answer 9

The joining of nuclei to release energy

Question 10

What is background radiation?

Answer 10

Radiation that is always present around us in the environment

Question 11

What is an artificial source of background radiation?

Answer 11

X-rays used in medical procedures

Question 12

How do radiation detectors work?

Answer 12

Detect the presence of ions or the chemical changes they produce

Question 13

What are 5 examples of radiation detectors?

Answer 13

1. Photographic film
2. Geiger-Muller (GM) tubes
3. Ionisation chambers
4. Scintillation chambers
5. Spark chambers

Question 14

What are 3 types of radiation?

Answer 14

1. Alpha particles
2. Beta particles
3. Gamma rays

Question 15

What is the nature of alpha particle emissions?

Answer 15

High energy

Question 16

What is the nature of beta particle emissions?

Answer 16

High energy

Question 17

What is the nature of gamma ray emissions?

Answer 17

High energy electromagnetic waves

Question 18

What is the ionising effect of an alpha particle?

Answer 18

Very strong

Question 19

What is the ionising effect of a beta particle?

Answer 19

Weak

Question 20

What is the ionising effect of a gamma ray?

Answer 20

Very weak

Question 21

What is the relative penetrating ability of an alpha particle?

Answer 21

Stopped by paper

Question 22

What is the relative penetrating ability of a beta particle?

Answer 22

Stopped by a few mm of aluminium

Question 23

What is the relative penetrating ability of a gamma ray?

Answer 23

Only reduced by lead

Question 24

Describe the deflection of alpha particles in a magnetic field

Answer 24

Slightly deflected

Question 25

Describe the deflection of beta particles in a magnetic field

Answer 25

Greatly deflected

Question 26

Describe the deflection of gamma rays in a magnetic field

Answer 26

No deflection

Question 27

Describe the deflection of alpha particles in an electric field

Answer 27

Slightly deflected

Question 28

Describe the deflection of beta particles in an electric field

Answer 28

Greatly deflected

Question 29

Describe the deflection of gamma rays in an electric field

Answer 29

No deflection

Question 30

Why are alpha and beta particles ionising?

Answer 30

They are charged

Question 31

What is a natural source of background radiation?

Answer 31

Underground rocks

Question 32

Why are beta particles deflected more than alpha particles?

Answer 32

They have a significantly smaller mass

Question 33

What are 4 applications of radiation?

Answer 33

1. Measuring the thickness of materials 2. Tracers 3. Radiotherapy 4. Sterilisation

Question 34

Which particles are used to measure the thickness of materials?

Answer 34

Beta

Question 35

What is radioactive decay?

Answer 35

Spontaneous disintegration of an unstable nucleus into a more stable one

Question 36

What happens during α- or β-decay?

Answer 36

The nucleus changes to that of a different element

Question 37

What is meant by the half-life of a radioactive isotope?

Answer 37

Time taken for the activity of any given sample to fall to half its original value

Question 38

What are the effects of ionising radiations on living | things?

Answer 38

1. Causes mutations 2. Causes cancer 3. Kills the cell

Question 39

Describe how radioactive materials can be handled in a safe way

Answer 39

Pick up with a pair of tongs

Question 40

Describe how radioactive materials can be used in a safe way

Answer 40

It is left out of its container for as short a time as possible

Question 41

Describe how radioactive materials can be stored in a safe way

Answer 41

Store in a lead container