Determine the number of atoms that would make up a 44.9 g sample of Selenium.

Question

Determine the number of atoms that would make up a 44.9 g sample of Selenium.

Answer 1

Atomic mass of selenium (Se) = 78.96 g / mol

mols Se = 44.9 g x 1 mol / 78.96 g = 0.5686 mols

Atoms of Se = 0.5686 mols x 6.022x10²³ atoms / mol = 3.42x10²³ atoms of Se