| Method |
Precise Learning Objective |
Linked |
Question / Activity
(Designed for maximum working out) |
Stepping Stones |
Pitstop Check
(Thinking Map) |
|
Radioactive decay is random. |
|
How radioactive decay happen? Model the radioactive decay of alpha and beta sources. Use the model to construct decay equations for alpha and beta decay. Critically analyse the limitations of the models produced by the class.
Demonstrate the randomness of the decay of a radioactive substance by throwing six dice and getting a prediction of the number of dice that will land on a six. Alternatively, drop 20 coins and get students to predict the number that will land on a head. |
|
|
|
The half-life of a radioactive isotope is the time it takes for the number of nuclei of the isotope in a sample to halve, or the time it takes for the count rate (or activity) from a sample containing the isotope to fall to half its initial level. |
|
What is the meaning of the term 'half-life'? |
|
|
|
Students should be able to explain the concept of half-life and how it is related to the random nature of radioactive decay |
|
How is the concept of half-life related to radioactive decay? Investigate half-life by throwing a large number of Tillich bricks. Any that land on the side with the odd colour get removed and the number remaining is recorded. Plot a graph of the number of throws against number of cubes remaining. Determine the half-life of the cubes (the number of throws needed to get the number of cubes to reduce by half).
This experiment can also be carried out using coins. Is it possible to predict which cubes or coins will land on a certain side? |
|
|
|
Students should be able to determine the half-life of a radioactive isotope from given information. |
|
How would the half-life of a radioactive isotope be determined from given information? |
|
|
|
(HT only) Students should be able to calculate the net decline, expressed as a ratio, in a radioactive emission after a given number of half-lives. |
|
How would the net decline of radioactive emission after a given number of half-lives be expressed? |
|
|