20.8 Half-Life
The activity of a radioactive material is the rate at which its atoms decay. It is measured in Becquerels (Bq), where 1 Bq = 1 disintegration per second, or in Curies (Ci), where 1 Ci = 3.7 × 10¹⁰ disintegrations per second.
The half-life of a radioactive isotope is the time it takes for half of the radioactive atoms in a sample to decay into a more stable form. Each isotope has a unique half-life that does not change.
N = N₀ × (1/2)ⁿ
where n = Δt / T₁/₂