Radioactive Decay

Radioactive Decay

RI-02
ASPCSPAdvanced

Formula
\[ A = A_0 \times e^{\displaystyle -\frac{0.693\,t}{T_{1/2}}} \]
When to Use

Calculate residual radioactivity of a source after a period of time.

Symbol Legend
SymbolMeaningUnitNote
ARadioactivity remaining at time tCi or Bq
A₀Initial radioactivityCi or Bq
eNatural log base2.718
0.693ln2natural log of 2 — Constant
tElapsed timesame units as T½

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