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Calculators

Solve any of N₀, N(t), half-life, or elapsed time for first-order decay — radioactive isotopes and drug clearance

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Solve for

Initial quantity (N₀)

Half-life (T₁/₂)

Elapsed time (t)

Remaining quantity

Decay constant λ = ln(2) / T₁/₂ = 1.3863e-1 per unit time

N(t) = N₀ × (1/2)^(t / T₁/₂). Works for any first-order decay: radioactive isotopes, drug clearance, or chemical reactions.

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