Answer:
14.77 mol.
Explanation:
Using cross multiplication:
1.0 mole of He contains → 6.022 x 10²³ atoms.
??? mole of He contains → 8.84 x 10²⁴ atoms.
∴ The no. of moles of He contains (8.84 x 10²⁴ atoms) = (1.0 mol)(8.84 x 10²⁴ atoms)/(6.022 x 10²³ atoms) = 14.77 mol.