Gamma radiation can be significantly reduced by...
A sheet of paper
A 3 mm thickness of aluminium
Several cm of lead
Gamma radiation is...
An electromagnetic wave
A helium nucleus
An electron
Higher tier only
Which form of radiation has the highest ionising power?
Gamma
Beta
Alpha
What causes an atom's nucleus to become unstable?
Too many or too few neutrons in the nucleus
More electrons than protons
Fewer electrons than protons
What is the activity of a source that emits 1,200 particles per minute?
20 Bq
1200 Bq
72,000 Bq
Which type of radiation has the greatest range in air?
What is background radiation?
Background radiation is heat from an electric blanket.
Background radiation is radiation that is always present in our environment and surroundings.
Background radiation is sound energy entering your house from outside.
What is the half-life of a radioactive source?
Half the age of the source
The time taken for the activity of the source to fall to half the original activity
Half the time taken for the activity of the source to fall to zero
A radioactive source has an activity of 3600 Bq and a half-life of 14 days. What is the activity of the source 42 days later?
450 Bq
900 Bq
A radioactive sample has a count rate of 10,000 Bq. 24 days later the activity has fallen to 625 Bq. What is the half-life of the sample?
4 days
6 days
12 days