Physics A-Level
Half-life
What Half-life means in Physics A-Level, as defined for AQA, OCR.
Definitions of Half-life
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Reference: OCR
The average time taken for half the nuclei in a sample to decay, or for the activity to halve, and is a constant for a given isotope.
The time in which activity halves, so it never reaches exactly zero in a finite time.
Topics that use Half-life
- Radioactive decay (A-level only) (AQA A-Level)
- Radioactivity (OCR A-Level)
Related terms
- Radioactive dating
- Absorber
- Alpha decay
- Beta-minus decay
- Beta-plus decay
- Carbon-14 and half-life
- Corrected count rate
- Decay constant
Using Half-life in the exam
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