Physics > Topic 3 - Radioactivity and Astronomy > Flashcards

Topic 3 - Radioactivity and Astronomy Flashcards

(50 cards)

Start Studying
1
Q

Who came up with the Plum Pudding Model of the Atom?

A

JJ Thompson

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

How was the Plum Pudding Model debunked?

A
  • Alpha particles fired at it
  • They expected them to pass through
  • However, some bounced directly back
  • This showed that there was a large concentration of positive charge in the centre
  • So the Plum Pudding Model was wrong
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What did the alpha particle experiment lead to the invention of?

A

The Nuclear Model of the Atom

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

Who came up with the current model of the Atom?

A

Niels Bohr

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

What is another name for an electron energy level?

A

Shell

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

What happens to an electron if it absorbs EM radiation?

A

It moves up an energy level

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

What happens to an electron if it emits EM radiation?

A

It moves down an energy level

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

When is an atom ionised?

A

When it gains or loses electrons

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

Finish the sentence: Nuclear radiation _______ atoms

A

Ionises

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

What are alpha particles?

A

Helium Nuclei

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

What are the 4 types of nuclear radiation?

A
  • Alpha
  • Beta-Minus
  • Beta-Plus
  • Gamma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the relative ionising powers of the 4 types of nuclear radiation?

A
  • Alpha: High
  • Beta-Minus: Moderate
  • Beta-Plus: Moderate
  • Gamma: Weak
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the relative travelling distances of the 4 types of nuclear radiation?

A
  • Alpha: Short
  • Beta-Minus: Moderate
  • Beta-Plus: Short
  • Gamma: Long
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are gamma rays?

A

EM Waves with a Short Wavelength

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

What do nuclear equations show?

A

Radioactive decay

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

Finish the sentence: The radioactivity of a source _________ over time

A

Decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Is radioactivity a random or systematic?

A

Random

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the half-life of a radioactive source?

A

The average time taken for the number of radioactive nuclei in an isotope to halve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How do you find a half-life on a graph?

A

Draw a line halfway down the y-axis, and match it will the time point on the x-axis. This is the half-life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are 3 sources of background radiation?

A
  • Naturally occurring unstable isotopes
  • Cosmic rays from space
  • Human activities (e.g. nuclear fallout)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is irradiation?

Study These Flashcards
A

Exposure to radiation, simply by being near to it

22
Q

How can irradiation from a radioactive source be prevented?

Study These Flashcards
A

By keeping it inside of a lead box

23
Q

What is contamination?

Study These Flashcards
A

Radioactive particles getting onto an object

24
Q

How can contamination be prevented?

Study These Flashcards
A

Using gloves and tongs when handling radioactive sources

25
What does a low-dose of radiation cause?
Cancer, as it mutates the cells
26
What does a high-dose of radiation cause?
Dead cells, causing radiation sickness
27
Outside the body, which types of radiation are the most damaging?
Beta and gamma as they have the most penetrating power
28
Inside the body, which type of radiation is the most damaging?
Alpha, as it is the most ionising, so it will do all of its damage in a localised area
29
Finish the sentence: The lower the activity of a source, the _____ it is to be around
Safer
30
What is a use of alpha radiation?
Household fire alarms
31
What is a use of gamma radiation?
Sterilisation
32
What is a use of beta radiation?
Thickness control of paper
33
How does a PET scanner work?
- Patient is injected with Fluorine-18 - Positrons emitted by the isotope annihilate with electrons, releasing gamma rays - Gamma rays are detected by the scanner - This shows where a tumour is
34
How does nuclear fission work?
A slow moving neutron is fired at a uranium-235 nucleus. This splits it into two daughter nuclei and releases 3 neutrons, which go on to split more unstable nuclei. This creates the chain reaction
35
In what two ways is nuclear fission controlled?
- Moderators slow down the neutrons | - Control rods limit the rate of fission by absorbing neutrons
36
How does nuclear fusion work?
Joins two small nuclei together, releasing energy in the form of gamma radiation
37
Why can we not do nuclear fusion on Earth?
It only happens at very high pressures and temperatures, and we cannot reach these
38
What are the pros of nuclear power?
- Very reliable - Relatively safe - Clean source of energy - Huge amounts of energy are created from a small amount of material
39
What are the cons of nuclear power?
- Lots of waste produces | - Nuclear meltdowns
40
What 6 types of object, other than the Sun, are in our Solar System?
- Planets - Dwarf Planets - Moons - Satellites - Asteroids - Comets
41
WHat provides the force that keeps objects in orbit?
Gravity
42
What are the three ideas about the Solar System in order?
- Geocentric - Earth in the middle - Heliocentric - Sun in the middle, circular orbits - Now - Sun in the middle, elliptical orbits
43
What are the two theories for the creation of the universe?
- Big Bang Theory | - Steady State Theory
44
What is red-shift?
The idea that everything is constantly moving away at different speeds
45
What theory does CMBR provide evidence for?
Big Bang Theory
46
What are the first three stages in the life cycle of a star?
- Nebula - Protostar - Main sequence star
47
For our sun, what will the next 2 stages of its life be?
- Red Giant | - White Dwarf
48
For a star much bigger than our sun, what will the next 3 stages of its life be?
- Red Supergiant - Supernova - Neutron star or Black hole
49
How can the quality of telescopes be improved?
- Increase the aperture of the telescope (diameter) | - Use a higher quality objective lens
50
Why do space telescopes have a clearer view than those on Earth?
- Light pollution | - Earth's atmosphere gets in the way as it absorbs lots of the light coming from space before it reaches us

Physics (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions