Question

If there are 520 grams of radioactive material with a half-life of 12 hours, how much of the radioactive material will be left after 72 hours? Is the radioactive decay modeled by a linear function or an exponential function?

Answer 1

Exponential! Hope it helps

Answer 2

`\bf \textit{Amount for Exponential Decay using Half-Life} \\\\ A=P\left( (1)/(2) \right)^{(t)/(h)}\qquad \begin{cases} A=\textit{accumulated amount}\\ P=\textit{initial amount}\to &520\\ t=\textit{elapsed time}\to &72\\ h=\textit{half-life}\to &12 \end{cases} \\\\\\ A=520\left( (1)/(2) \right)^{(72)/(12)}\implies A=520\left( (1)/(2) \right)^6\implies A=8.125`

is it linear or exponential? well, look above.