If the measured mass of an element is numerically equal to its molar mass, then you have indirectly counted 6.02 x 1023 atoms of the element in the measurement. For each problem in Column A, select from Column B the letter of the conversion factor needed to solve the problem. (NOTE: Two questions have two answers.) Column A Column B 20. Find the number of moles in 23.0 g of zinc. 21. Find the mass of 5.0 x 1020 zinc atoms. 22. Find the mass of 2.00 moles of zinc. 23. Find the number of atoms in 7.40 g of zinc. 24. Find the number of moles that contain 4.25 x 1027 zinc atoms. 25. Find the number of atoms in 3.25 moles of zinc. a. 65.4g Zn/1 mol Zn b. 1 mol Zn/65.4g Zn c. 6.02 x 1023 atoms Zn/1 mol Zn d. 1 mol Zn/6.02 x 1023 atoms Zn