Question

the half-life of a radioactivity kind of radium is 11 days. if you start with 1,488 grams of it, how much will be left 22 days??

Answer 1

372 grams

Step-by-step explanation

The half life of the substance is 11 days.

We want to find how much will be left after starting with 1488 grams for 22 days.

To do that, apply the formula for half life:

`N=N_0((1)/(2))^{\frac{t}{T_{}}}`

where N = amount of substance left

N0 = initial amount of substance

t = amount of time

t1/2 = hlaf life

Therefore, for the given substance, the amount that will be left after 22 days is:

`\begin{gathered} N=1488\cdot((1)/(2))^{(22)/(11)} \\ N=1488\cdot((1)/(2))^2 \\ N=1488\cdot(1)/(4) \\ N=372\text{grams} \end{gathered}`