Nuclear Physics Details

Question 1

Structure of an atom

Answer 1

-Contains a positively charged nucleus(surrounded by mostly empty space)
-There are negatively charged electrons orbiting around the nucleus

Question 2

Protons and neutrons are bound together by a…

Answer 2

strong nuclear force

Question 3

Regarding mass, the nucleus contains…

Answer 3

most of the mass of an atom(the electrons barely have any mass)

Question 4

Relative charge of protons

Answer 4

+1

Question 5

Relative charge of electrons

Answer 5

-1

Question 6

Relative charge of neutrons

Answer 6

0

Question 7

Sources that significantly contribute to background radiation

Answer 7

-Radon gas(in the air)
-Rocks and buildings
-Food and drink
-Cosmic rays

Question 8

How ionising nuclear radiation can be measured

Answer 8

Using a detector connected to a counter

Question 9

Nature of the emission of radiation from a nucleus

Answer 9

Spontaneous and random in direction

Question 10

Types of nuclear radiation

Answer 10

-Alpha particles
-Beta particles
-Gamma rays

Question 11

Description of alpha particles

Answer 11

Each particle is 2 protons + 2 neutrons(identical to a nucleus of helium-4)

Question 12

Description of beta particles

Answer 12

Each particle is an electron(created when the nucleus decays)

Question 13

Description of gamma rays

Answer 13

Electromagnetic waves(similar to X-rays)

Question 14

Relative charge of alpha particles

Answer 14

+2

Question 15

Relative charge of beta particles

Answer 15

-1

Question 16

Relative charge of gamma rays

Answer 16

0

Question 17

Mass of alpha particles

Answer 17

High(compared to beta particles)

Question 18

Mass of beta particles

Answer 18

Low

Question 19

Mass of gamma rays

Answer 19

No mass

Question 20

Speed of alpha particles

Answer 20

Up to 0.1× the speed of light

Question 21

Speed of beta particles

Answer 21

Up to 0.9× the speed of light

Question 22

Speed of gamma rays

Answer 22

Speed of light

Question 24

Ionizing effect of alpha particles

Answer 24

Strong

Question 24

Ionizing effect of gamma rays

Answer 24

Very weak

Question 25

Ionizing effect of beta particles

Answer 25

Weak

Question 26

Penetrating effect of alpha particles

Answer 26

Not very penetrating(stopped by a thick sheet of paper, or by skin, or by a few centimetres of air)

Question 27

Penetrating effect of beta particles

Answer 27

Penetrating(stopped by a few millimetres of aluminium or other metal)

Question 28

Penetrating effect of gamma rays

Answer 28

Very penetrating(never completely stopped, though lead and thick concrete reduce its intensity)

Question 29

Effect of magnetic/electric fields on alpha particles

Answer 29

Deflected by magnetic and electric fields

Question 30

Effect of magnetic/electric fields on beta particles

Answer 30

Deflected by magnetic and electric fields

Question 31

Effect of magnetic/electric fields on gamma rays

Answer 31

Not deflected by magnetic and electric fields

Question 32

Symbol for alpha particles

Answer 32

α

Question 33

Symbol for beta particles

Answer 33

β–

Question 34

Symbol for gamma rays

Answer 34

γ

Question 35

(In terms of ionizing effect)The greater the charge of the radiation...

Answer 35

the more ionising it is

Question 36

(In terms of ionizing effect)The greater the kinetic energy of the radiation...

Answer 36

the more ionising it is

Question 37

Why isotopes of an element may be radioactive

Answer 37

There may be an excess of neutrons in the nucleus and/or the nucleus may be too heavy

Question 38

Effect of α-decay, β-decay and γ-emissions on the nucleus

Answer 38

-Increase in stability -Reduction in the number of excess electrons

Question 39

What happens in alpha decay

Answer 39

An alpha particle(2 neutrons + 2 protons) leaves the nucleus(with 2 protons and 2 neutrons less than before)

Question 40

What happens in beta decay

Answer 40

-A neutron in the nucleus is converted into a proton and an electron -The electron is fired out of the nucleus whilst the proton remains

Question 41

Uses of radioactive isotopes

Answer 41

-Household fire(smoke) alarms(Americium-241) -Irradiating food to kill bacteria -Sterilisation of equipment using gamma rays -Diagnosis and treatment of cancer using gamma rays -Tracers(iodine isotopes) -Radioactive dating(carbon and uranium isotopes)

Question 42

Effects of ionising nuclear radiation on living things

Answer 42

-Cell death -Mutations -Cancer

Question 43

Safety precautions for ionising radiation

Answer 43

-Reducing exposure time -Increasing distance between source and living tissue -Using shielding(eg. lead barriers) to absorb radiation