The half-life of a radioactive kind of element is 18 minutes. How much will be left after 36 minutes, if you start with 32 grams of it?

There will be 8 grams left after 36 minutes.

Step-by-step explanation:

A half-life is how long it takes for half of the amount to go away. In this case, we see that we have two half-life periods worth, which you can determine by dividing the total time by the half-life time.

36mins/16mins = 2 half lives.

Now we can raise 1/2 to the power of how many half lives we have (2). Then we multiply that by the amount in the sample.

(1/2) ^2 * 36

1/4 * 36

8 grams

It's gonna be 8 grams