Nuclear Decay

Question 1

Isotope

Answer 1

An element with the same number of protons, but a different number of neutrons

Question 2

Nuclear Decay

Answer 2

Spontaneous emission of energy of alpha, beta, gamma by an unstable nucleus to become more stable

Question 3

Half life

Answer 3

The time taken for the number of radioactive nuclei to halve

Question 4

Decay constant

Answer 4

The fraction of nuclei that will decay per second

Question 5

Activity

Answer 5

The rate of decay of a sample of radioactive nuclei

Question 6

What unit is used for Activity

Answer 6

Becquerel (Bq)

Question 7

What is an Alpha radiation particle

Answer 7

A helium nucleus

Question 8

What is a Beta radiation particle

Answer 8

A High speed electron

Question 9

What is Gamma radiation

Answer 9

An Electromagnetic Wave

Question 10

What is the charge of an Alpha particle

Answer 10

2+

Question 11

What is the charge of a Beta Particle

Answer 11

1-

Question 12

What is the charge of a gamma wave

Answer 12

0

Question 13

What is the definition of half life

Answer 13

The time taken for half the number of radioactive nuclei present to decay

Question 14

What is the penetration, like of an Alpha particle

Answer 14

low

Question 15

What is the penetration, like of a Beta particle

Answer 15

medium

Question 16

What is the penetration, like of a Gamma wave

Answer 16

High

Question 17

What is the change in nucleon and proton number when an Alpha particle is emitted

Answer 17

nucleon = -4
proton = -2

Question 18

What is the change in nucleon and proton number when a Beta particle is emitted

Answer 18

nucleon = 0
proton = +1

Question 19

Does Gamma radiation effect Nucleon and Proton Numbers, why?

Answer 19

No, since it does not have a charge

Question 20

What types of radiation are effected by electric/magnetic fields

Answer 20

Alpha and Beta

Question 21

Why do highly ionising particles have low penetration power

Answer 21

The particle interacts strongly with matter i passes through. So in each interaction some KE is absorbed by the matter. Which reduces its penetrating power.

Question 22

What is the first reason Alpha particles are highly ionising when compared to Beta particles, why

Answer 22

They have a higher charge than Beta
So they interact more strongly with other charged particles

Question 23

What is the second reason Alpha particles are highly ionising when compared to Beta particles, why

Answer 23

They have a larger mass
So they are more likely to collide with other particles

Question 24

What is the Third reason Alpha particles are highly ionising when compared to Beta particles, why

Answer 24

They move slower
So they increase the likelihood of interacting with other particles

Question 25

Why are gamma particles weakly ionising

Answer 25

They have no charge and no rest mass, High frequency so electrons cannot move fast enough to interact with them

Question 26

Describe the theory behind the first method to distinguishing between the radiations.

Answer 26

The three radiations have different penetrating powers, we use this to filter the radiations, with a counter detecting changes.

Question 27

Describe the theory behind the second method to distinguishing between the radiations

Answer 27

Since Alpha and Beta particles have opposite charges they move in different directions through electric/magnetic fields. A carefully placed Geiger counter can be used to detect the different radiations.

Question 28

What is the equation for the activity of a radioactive nuclei

Answer 28

A = -λN N = Number of nuclei λ = Decay constant

Question 29

What are the two similar equations that can be used to find the number of radioactive nuclei and activity

Answer 29

N = N_0e^(-λt) A = A_0e^(-λt)

Question 30

What is the equation for Decay constant

Answer 30

λ = (ln(2))/(half life)