Asample of 37ar undergoes 8540 disintegrations/min initially but undergoes 6990 disintegrations/min after 10.0 days. what is the half-life of 37ar in days?

Explanation:

Expression for rate constant and half-life is as follows.

            k =

The given data is as follows.

         a = 8540 disintegrations/min

and,   (a - x) = 6990 disintegrations/min

Putting the given values into the above formula as follows.

       k =

           = 0.02

Now, we will calculate the half-life as follows.

      Half-life =

                   = 34.6 days

Thus, we can conclude that the half-life of 37Ar in days is 34.6 days.

the answer is d.) potassium