Chemistry — Half-life by Reaction Order

\text{zero order: } t_{1/2} = \frac{[\text{A}]_0}{2k}

\text{first order: } t_{1/2} = \frac{\ln 2}{k}

\text{second order: } t_{1/2} = \frac{1}{k[\text{A}]_0}

\text{first-order } t_{1/2} \text{ is constant}