Radioactivity Flashcards

1
Q

What is meant by the decay constant of an isotope?

A

The decay constant is the probability of decay of a nucleus per unit time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What happens to the mass number of a nucleus when it undergoes alpha decay?

A

-4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What happens to the proton number of a nucleus when it undergoes alpha decay?

A

-2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What happens to the mass number of a nucleus when it undergoes beta decay?

A

Nothing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What happens to the proton number of a nucleus when it undergoes beta - decay?

A

+1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What happens to the proton number of a nucleus when it undergoes beta + decay?

A

-1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is an alpha particle?

A

Two protons two neutrons bound together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a beta + particle?

A

A positron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a beta - particle?

A

An electron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is gamma radiation?

A

High frequency photon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the penetration depth of alpha particles?

A

Thin sheet of paper, a few centimetres of air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the penetration depth of beta - particles?

A

1-3 mm of aluminium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the penetration depth of beta + particles?

A

VERY short because they are annihilated by electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the penetration depth of gamma particles?

A

Reduced by a few cm of lead

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is produced in an alpha decay?

A

A single alpha particle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is produced in a beta + decay?

A

A positron and a neutrino

17
Q

What is produced in a beta - decay?

A

An electron and an antineutrino

18
Q

What does random mean, in the context of a decay?

A

We are unable to predict when a particular nucleus in a substance will decay or which one will decay next.

19
Q

What does spontaneous mean, in the context of a decay?

A

The decay of nuclei is not affected by the presence of other nuclei in the substance or external factors.

20
Q

What is the atomic mass unit?

A

A 1/12 of the mass of the nucleus of a carbon-12 nucleus.

21
Q

What is radioactive activity?

A

The number of decays per unit time

22
Q

What is the conservation of lepton number?

A

The total Lepton Number before a nuclear change will equal the total Lepton number after.

23
Q

What is the conservation of baryon number?

A

The total Baryon Number before a nuclear change will equal the total Baryon Number after.

24
Q

What is the binding energy?

A

The energy required to disassemble the protons and neutrons in a nucleus into their separate parts.

25
Q

What is a half-life?

A

The time taken for the activity of a substance to reduced to 50% of its value.