Activity and half-life calculations
I can interpret radioactive half-life graphs and make calculations using values of half-life.
Activity and half-life calculations
I can interpret radioactive half-life graphs and make calculations using values of half-life.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- The amount (or activity) of a radioactive isotope repeatedly falls by half in equal amounts of time.
- A radioactive half-life graph shows the amount (or activity) of a radioactive isotope plotted against time.
- In 2 half-lives the amount (or activity) of a radioactive isotope falls to ½ × ½ = ¼ as much.
- In 3 half-lives the amount (or activity) of a radioactive isotope falls to ½ × ½ × ½ = 1/8 as much, and so on.
- Radioactive isotopes with short half-lives decay quickly, emitting most radiation over a short period of time.
Keywords
Activity - the number of decays per second; it is measured in becquerels (Bq)
Radioactive isotopes - contain unstable nuclei that will decay over time and emit ionising radiation
Radioactive half-life - the time taken for the activity of a sample of a radioactive isotope to halve
Common misconception
It is impossible to predict outcomes for random events such as radioactive decay.
Use analogies to show that random nuclear decay can lead to predictable outcomes, such as the randomness in the order popcorn kernels pop, but the predictability of how quickly all the popcorn takes to cook.
Content guidance
- Depiction or discussion of sensitive content
Supervision
Adult supervision recommended
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
Loading...
Starter quiz
6 Questions
0 hours
10 hours
20 hours
30 hours
Exit quiz
6 Questions
0 mins
5 mins
10 mins
15 mins
20 mins
25 mins