Radioactivity - Multiple choice questions

Multiple choice questions appear in both exam papers, and at both Tiers. Multiple choice questions are asked as questions, often starting with 'What is …' or 'Which of these …'.

You have four options to choose from in a multiple choice question. You must only choose one of these options, by writing your answer (A, B, C, or D) in a box.

It may help to reject any answers that you feel are obviously wrong, so that you can focus on choosing the right answer.

Sample question 1 - Foundation

Question

What is the number of neutrons in this isotope of uranium? [1 mark]

_{92}^{238}U

A92
B119
C146
D238

OCR Gateway Science, GCE Physics, Paper J249, 2016.

A92
B119
C146
D238

Sample question 2 - Foundation

Question

All radioactive sources have a half-life.

Which statement about the half-life of a source is correct? [1 mark]

AIt is half the time for the radioactive source to become safe
BIt is half the time it takes for an atom to decay
CIt is half the time it takes the activity of the source to decrease to zero
DIt is the time it takes the activity of the source to decrease by half

OCR Gateway Science, GCE Physics, Paper J249, 2016.

AIt is half the time for the radioactive source to become safe
BIt is half the time it takes for an atom to decay
CIt is half the time it takes the activity of the source to decrease to zero
DIt is the time it takes the activity of the source to decrease by half

Sample question 3 - Higher

Question

Which statement describes nuclear fusion? [1 mark]

ATwo hydrogen nuclei join to form a helium nucleus
BA helium nucleus joins with a hydrogen nucleus to form an alpha particle
CUranium nuclei split and produce high energy neutrons causing a chain reaction
DTwo helium nuclei join to form a hydrogen nucleus

OCR Gateway Science, GCE Physics, Paper J249, 2016 - Higher.

ATwo hydrogen nuclei join to form a helium nucleus
BA helium nucleus joins with a hydrogen nucleus to form an alpha particle
CUranium nuclei split and produce high energy neutrons causing a chain reaction
DTwo helium nuclei join to form a hydrogen nucleus

Sample question 4 - Higher

Question

A radioactive source has a half-life of 80 s.

How long will it take for 7/8 of the source to decay? [1 mark]

A10 s
B70 s
C240 s
D640 s

OCR Gateway Science, GCE Physics, Paper J249, 2016 - Higher.

A10 s
B70 s
C240 s
D640 s