Nuclear Decay and Energy

Question 1

What is a radioactive element?

Answer 1

Radioactive elements are unstable elements which are made up of atoms with unstable nuclei that are emitting ionising radiation by spontaneous disintegration in aims of attaining a stable form

Question 2

What is nuclear decay?

Answer 2

Nuclear decay is the inevitable decay of an element to form a stable element, as the nucleus of the decaying atom changes during the dexay

Question 3

What is true about radioactive emission?

Answer 3

It is spontaneous and random

Question 4

Where is radioactive radiation emitted from?

Answer 4

The nucleus of the atom

Question 5

What are the 3 types of radiation?

Answer 5

Alpha α
Beta β
Gamma Υ

Question 6

What is alpha radiation?

Answer 6

An alpha particle is a fast moving helium nucleus

Question 7

What is the mass of an alpha particle?

Answer 7

4u

Question 8

What is the charge of an alpha particle?

Answer 8

2+

Question 9

What is the range and penetration of an alpha particle?

Answer 9

Short range, stopped by 2cm of air

Question 10

What is the ionisation of an alpha particle?

Answer 10

High, an alpha particle is strongly ionising

Question 11

What is the speed of an alpha particle?

Answer 11

An alpha particle is fast moving

Question 12

Do alpha particles get deflected by electric or magnetic fields?

Answer 12

Yes, alpha particles are weakly deflected by E and B fields

Question 13

What is a beta particle?

Answer 13

A high energy electron

Question 14

What is the mass of a beta particle?

Answer 14

1/2000u

Question 15

What is the charge of a beta particle?

Answer 15

-1

Question 16

What is the range and penetration of a beta particle?

Answer 16

Medium range, stopped by 2-3mm of aluminium

Question 17

What is the ionisation of beta particle?

Answer 17

Medium, a beta particle is moderately ionising

Question 18

What is the speed of a beta particle?

Answer 18

A beta particle moves just less than the speed of light

Question 19

Do beta particles get deflected by electric or magnetic fields?

Answer 19

Yes, beta particles are strongly deflected by E & B fields because of their low mass

Question 20

What is a gamma particle?

Answer 20

High energy photon γ

Question 21

What is the mass of a gamma particle?

Answer 21

Gamma particles are massless

Question 22

What is the charge of a gamma particle?

Answer 22

Gamma particles have no charge

Question 23

What is the range and penetration of a gamma particle?

Answer 23

Long range, stopped by 2-3cm of lead

Question 24

What is the ionisation of a gamma particle?

Answer 24

A gamma particle is weakly ionising

Question 25

What is the speed of a gamma particle?

Answer 25

A gamma particle moves at the speed of light

Question 26

Do gamma particles get deflected by electric and magnetic fields?

Answer 26

No

Question 27

What is half life?

Answer 27

The time taken for the activity of a radioactive substance to decay by half

Question 28

The activity (A) is proportional to?

Answer 28

The number of radioactive nuclei (N)

Question 29

What is the equation of activity and number of radioactive nuclei?

Answer 29

A = -λN Where λ is the decay constant

Question 30

What are the decay equations?

Answer 30

A = A°e^-λt N = N°e^-λt

Question 31

What is the activity of a radioactive nuclei?

Answer 31

The rate of decay of a sample of radioactive nuclei

Question 32

What is the equation for finding the number of unstable nuclei after a time t, if the number of half lives is known?

Answer 32

N = N°/2^x A = A°/2^x

Question 33

What is the equation for half life?

Answer 33

T = ln(2)/λ

Question 34

What is activity measured in?

Answer 34

Bq (becquerels)

Question 35

What is the decay constant?

Answer 35

The probability that a single nucleus will decay per unit time

Question 36

What is true about energy and mass?

Answer 36

They are equivalent: E = mc^2

Question 37

In a nuclear reaction the energy produced is equivalent to what?

Answer 37

The energy produced is equivalent to the loss of mass

Question 38

What is binding energy?

Answer 38

The energy that has to be supplied to separate a nucleus into its individual nucleons

Question 39

What is a nucleon?

Answer 39

A proton or neutron

Question 40

What is true with a higher the binding energy of a nuclei?

Answer 40

The more stable the nuclei is

Question 41

Why are nuclei with a higher binding energy per nucleon more stable?

Answer 41

Because the binding energy per nucleon is energy required to overcome the strong nuclear force holding the nuclei’s nucleons together

Question 42

What happens when you input the binding energy to separate nucleons?

Answer 42

The separated nucleons have a slight increase in mass

Question 43

In both fusion and fission reactions what is true about the binding energy per nucleon of the product?

Answer 43

The binding energy per nucleon of the product is higher than the reactants

Question 44

How much energy is one “u” equal to?

Answer 44

931 MeV

Question 45

What is the mass defect?

Answer 45

The mass of a nucleus is smaller than the sum of the masses of the constituent nucleons, this difference is the mass defect