Lesson: Calculating the Activity of a Radioactive Source Physics • 9th Grade

Students will be able to

• understand that the activity of a radioactive sample decreases by equal factors over equal periods of time,
• define the half-life of a radioactive sample as the time it takes for the activity to reduce by half,
• work out the activity of a sample after a given number of half-lives has passed given the initial activity and vice versa,
• work out the number or proportion of radioactive atoms in a sample after a given number of half-lives has passed given the initial number or proportion of radioactive atoms in the sample and vice versa,
• work out the half-life of a sample from a graph of activity over time or tabular data of activity over time.