Radioactivity

Radioactivity

Revision resources

An old Q/A bit out of date

The syllabus

Revision Q/A

Radioactivity OCR syllabus

describe how the breakdown of an unstable nucleus results in radioactive emission and the formation of a new element.

recognise that a stable nucleus can become unstable by the absorption of neutrons.

explain that the level of background radiation, from a variety of sources, is higher in some places than in others.

describe how to take background radioactivity into account when performing experiments. .

recall the relative penetration of alpha, beta and gamma emissions.

apply this knowledge to explain why different emissions are suited to particular purposes including sterilisation, thickness measurement, treatment of cancer and tracer techniques.

describe alpha, beta and gamma emissions in terms of atomic particles and electromagnetic waves.

explain that the activity of a radioactive sample decreases with time.

attribute this decrease in activity to a corresponding decrease in the number of unstable nuclei.

explain half-life as the average time for the number of undecayed nuclei in a sample to halve.

explain that different radioactive materials decay at different rates.

use an activity-time graph to determine the half-life of a material.

describe how the half-life of a material can be measured.

apply an understanding of half-life to explain why different sources are suited to particular purposes.

explain how measurements of the amounts of radioactive elements and their decay products in rocks can be used to calculate the age of a rock.

interpret given information about developments in ideas of radioactivity. [No recall is expected.]

recall that exposure to ionising radiation can be harmful.

describe the precautions that should be taken when handling radioactive materials.

describe some effects of radiation on the human body.

explain how the effects of radiation depend on the energy and penetration of the emission as well as the amount of exposure.