Question

Cow’s milk produced near nuclear reactors can be tested for as little as 1.00 pCi of 131I per liter, to check for possible reactor leakage. What mass of 131I has this activity?

a) 3.70 x 10⁻⁹ g
b) 3.70 x 10⁻¹¹ g
c) 3.70 x 10⁻⁷ g
d) 3.70 x 10⁻⁵ g

Answer 1

The mass of 131I with an activity of 1.00 pCi per liter cannot be determined without knowing the half-life of 131I.

Step-by-step explanation:

The activity of a radioactive substance is measured in units called picocuries (pCi). In this case, the activity of 131I in cow's milk near nuclear reactors is 1.00 pCi per liter.

To find the mass of 131I with this activity, we need to convert from activity to mass using the relationship between activity, half-life, and Avogadro's number.

The formula to convert from activity to mass is: Mass (g) = Activity (Ci) x Half-Life (s) x Mol. Mass (g/mol) / Avogadro's Number (mol^-1).

Since the half-life of 131I is not provided, we cannot determine the mass of 131I with this activity.