Half-Life Calculations | GCSE Physics Practice
Half-life is the time it takes for half of the radioactive nuclei in a sample to decay.
If you wait two half-lives, how much of the sample remains?
What is Half-Life Calculations | Practice?
"The time taken for the radioactivity of a specified isotope to fall to half its original value."
What is the definition of half-life?
A sample has an activity of 800 Bq. After 2 half-lives, what will the activity be?
If a sample has a half-life of 4 days, what fraction remains after 12 days?
Half-Life Key Facts
It is a random process, but follows a predictable pattern for large samples.
Activity is measured in Becquerels (Bq).
One half-life = 50% remaining. Two = 25% remaining.
Math Tip: Activity always decreases over time. If your answer is higher than the starting value, you made a mistake!
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