Half-life (AQA GCSE Physics Combined Science): Quizzes
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Practise the questions
12 questions from this quiz
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Practise the questions
12 questions from this quiz
What is half-life?
What is half-life?
Time for half the unstable atoms to decay
What does the activity of a radioactive source tell us?
What does the activity of a radioactive source tell us?
How many atoms decay each second
What is the unit of measurement for activity?
What is the unit of measurement for activity?
Becquerels (Bq)
What percentage of original radioactive atoms remain after 2 half-lives?
What percentage of original radioactive atoms remain after 2 half-lives?
25%
A source with 240 Bq activity and 6-hour half-life. What is the activity after 18 hours?
A source with 240 Bq activity and 6-hour half-life. What is the activity after 18 hours?
30 Bq
What can we predict about radioactive decay?
What can we predict about radioactive decay?
Overall pattern for many atoms
What percentage of original atoms remain after 3 half-lives?
What percentage of original atoms remain after 3 half-lives?
12.5%
Why does activity decrease over time?
Why does activity decrease over time?
Fewer unstable atoms left to decay
What type of curve does a radioactive decay graph show?
What type of curve does a radioactive decay graph show?
Exponential decay curve
On a radioactive decay graph, what does the y-axis show?
On a radioactive decay graph, what does the y-axis show?
Activity in Bq
A source starts at 240 Bq. After how many half-lives does it reach 60 Bq?
A source starts at 240 Bq. After how many half-lives does it reach 60 Bq?
2
How do you find half-life from a graph?
How do you find half-life from a graph?
Find time for activity to halve