Half-life and exponential decay calculator

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Result

Amount left157

Decay constant k0.000121

Fraction left78.51 %

Step-by-step solution

Decay constant

k = ln 2/t_½ = 0.000121

Exponential decay

N = N₀·e^−kt = 200·e^{−0.000121·2000} = 157

Key formulas

Exponential growth/decay: dy/dt = ky → y = y₀e^kt
Half-life: k = ln 2 / t_½

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