Physics

Problem

^{19}\text{K}^{40}

consists of 0.012% of the potassium in nature. The human body contains 0.35% potassium by mass. Calculate the total radioactivity resulting from

^{19}\text{K}^{40}

decay in a 75 kg human. Half-life for

^{19}\text{K}^{40}

1.3 \times 10^9 \text{ year}