Isotope Ratio Calculator — calculate isotope ratio using standard chemistry formulas. Worked example with units.
Decay equation: N(t) = N₀ × e^(−λt), where λ = ln(2) / t½ (decay constant)
Activity: A = λ × N (decays per second = Becquerels, Bq) | 1 Curie = 3.7×10¹⁰ Bq
Remaining fraction: N(t)/N₀ = (½)^(t/t½)
Age from C-14: t = (t½ / ln 2) × ln(N₀/N(t)) ≈ 8,267 × ln(A₀/Aₜ) years