### Working with a radioactive material

The half life of Cl is 9.5 x 10(exponent 12)s. How many atoms of Cl are present in a sample with an activity of 1.5 x 10(exponent 9) atoms/s a. 2.1 x 10(exponent 22) atoms b. 6.3 x 10(exponent 3) atoms c. 4.9 x 10(exponent negative 23) atoms d. 1.4 x 10(exponent 22) atoms e. 7.0 x 10(exponent 23) atoms