Final answer:
To find the mass of 4.2 x 10^23 atoms of xenon (Xe), divide the number of atoms by Avogadro's number to get moles, then multiply by xenon's molar mass. The resulting mass is approximately 91.52 grams.
Step-by-step explanation:
To calculate the mass of 4.2 x 1023 atoms of xenon (Xe), we need to use Avogadro's number, which is approximately 6.02 x 1023 atoms per mole, and the molar mass of xenon, which is 131.3 g/mol. First, we determine the number of moles of xenon by dividing the number of atoms by Avogadro's number:
Number of moles = 4.2 x 1023 atoms / 6.02 x 1023 atoms/mol
This calculation gives us approximately 0.697 moles of xenon. Then, we multiply the number of moles by the molar mass of xenon to get the mass in grams:
Mass of xenon = 0.697 moles x 131.3 g/mol
Therefore, the mass of xenon is approximately 91.52 grams.