Difference between revisions of "Half Life"
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| + | ==Key Stage 4== | ||
| + | ===Meaning=== | ||
| + | A '''half life''' is the time it takes for half of the [[Unstable Isotope|unstable isotopes]] in a [[radioactive]] sample to [[Radioactive Decay|decay]]. | ||
| + | ===About Half Life=== | ||
| + | : Every [[isotope]] has a unique '''half life'''. | ||
| + | : The '''half life''' of an [[isotope]] depends on how [[Stable Isotope|stable]] the [[isotope]] is. | ||
| + | : The '''half life''' of an [[isotope]] can be determined by measuring the [[emission]] of [[Ionising Radiation|ionising radiation]]. The time it takes for the [[Count Rate|count rate]] of [[Ionising Radiation|ionising radiation]] to halve, is the '''half life'''. | ||
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Revision as of 01:54, 9 March 2019
Key Stage 4
Meaning
A half life is the time it takes for half of the unstable isotopes in a radioactive sample to decay.
About Half Life
- Every isotope has a unique half life.
- The half life of an isotope depends on how stable the isotope is.
- The half life of an isotope can be determined by measuring the emission of ionising radiation. The time it takes for the count rate of ionising radiation to halve, is the half life.
| Time /s | 0 | 10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 |
| Count rate /Bq | 1000 | 707 | 500 | 353 | 250 | 176 | 125 | 88 | 62 |
| Time /min | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| Count rate /Bq | 5000 | 3968 | 3150 | 2500 | 1984 | 1575 | 1250 | 992 | 788 |