Free Radioactive Activity Calculator
Calculate radioactive activity in Becquerels from the number of atoms and decay constant, with Curie conversion.
seconds
Activity
192,540,883,488.874 Bq
Activity5.204 Ci
Decay Constant (lambda)0.0002 1/s
Activity vs Number of Radioactive Atoms (N)
Radioactive Activity
Activity is the rate of radioactive disintegrations per second. One Becquerel (Bq) equals one disintegration per second.
Formula
A = lambda × N = (ln2 / t½) × N
where lambda is the decay constant and N is the number of radioactive atoms. The older unit Curie: 1 Ci = 3.7 × 10¹⁰ Bq (the activity of 1 gram of Ra-226).
Example Calculation
10¹⁵ atoms of an isotope with half-life 3600 seconds (1 hour).
- 01lambda = ln(2) / 3600 = 1.925 × 10⁻⁴ s⁻¹
- 02A = 1.925 × 10⁻⁴ × 10¹⁵ = 1.925 × 10¹¹ Bq
- 03A = 1.925 × 10¹¹ / 3.7 × 10¹⁰ = 5.20 Ci
Frequently Asked Questions
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