Which statement about nuclear fission is correct?
An example is when hydrogen is converted to helium.
It may happen when a nucleus absorbs a neutron.
The Sun uses fission to generate its energy.
Two nuclei join to make a heavier nucleus.
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1 markWhich scenario is an example of contamination?
An apple is exposed to gamma rays from a source 5 cm away. The apple is then eaten.
In a course of radiotherapy, gamma rays are aimed at a tumour in a patient.
A woman is renovating a house with old paint containing stable lead atoms. Some gets in her eye.
A worker inhales a small amount of radon gas which is unstable.
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1 markWhy is a large radioactive source with a short half-life hazardous?
It has a high activity
It will emit radiation for a short time
It emits more dangerous types of radiation
It will decay into another element
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The table gives some information about four radioactive isotopes.
Which isotope is the best to use as a medical tracer?
| Half life | Radiation emitted |
A | 6 hours | alpha |
B | 6 hours | gamma |
C | 6 minutes | gamma |
D | 6 years | beta |
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Which statement describes nuclear fusion?
A helium nucleus joins with a hydrogen nucleus to form an alpha particle.
Two helium nuclei join to form a hydrogen nucleus.
Two hydrogen nuclei join to form a helium nucleus.
Uranium nuclei split and produce high energy neutrons causing a chain reaction.
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1 markWhich of the following properties is desirable in an ingested (swallowed) medical tracer for the blood?
Long half-life
Alpha source
Gamma source
Very short half-life
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1 markHydrogen fusion requires very high energies.
Why is this?
To overcome the attractive force between nuclei.
The particles need a large potential energy.
To produce a bigger mass difference.
There is a strong repulsive force between positive nuclei.
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1 markWhich is the correct word equation for a stable chain reaction in nuclear fission?
neutron + uranium → daughter nuclei + 7 neutrons
3 neutrons + uranium → daughter nuclei + neutron
neutron + uranium → daughter nuclei + 2 neutrons
neutron + uranium → daughter nuclei
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Which statement about nuclear fusion is correct?
Energy is released because mass is converted to energy.
Helium is converted into hydrogen.
It is the main way in which nuclear power generates electricity.
It is the splitting of a heavy nucleus into smaller nuclei.
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1 markThe table below shows data for four different gamma sources.
The hospital's background radiation is 20 counts per minute.
Which is the most suitable medical tracer?
Source | Activity at t = 0 s (counts/min) | Activity at t = 60 s (counts/min) |
|---|---|---|
A | 50 000 | 720 |
B | 250 | 210 |
C | 36 | 24 |
D | 300 | 299 |
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