Answer: m = 5.81x10-²³ g Cl
Explanation: First is to find the number of moles of Cl in 1 atom of Chlorine. To solve this we will use the Avogadro's Number to convert atoms to moles.
1 atom Cl x 1 mole Cl / 6.022x10²³ atoms Cl
= 1.66x10-²⁴ moles Cl
The next step is to convert the moles of Cl to mass using its molar mass.
1.66x10-²⁴ moles Cl x 35 g Cl / 1 mole Cl
= 5.81x10-²³ g Cl.
Cancel out the units of moles Cl.