Exp decay

An element with a mass of 780 grams decays by 16.3% per minute. How much of the element is remaining after 16 minutes, to the nearest 10th of a gram?

Correct answer:

m₂ =  45.3 g

Step-by-step explanation:

$$\begin{gathered} m_1=780\text{g} \\ r=100\%-16.3\%=1-\frac{16.3}{100}=0.837 \\ t=16\text{min} \\ q=r^t=0.837^{16}\doteq 0.058 \\ {m}_2=m_1\cdot q=780\cdot 0.058=45.3\text{g} \end{gathered}$$

Try another example