Hello!
To find the number of atoms in 2.822 moles of nickel, we need to multiply it by Avogadro's number. Avogadro's number is 6.02 x 10^23 atoms.
2.822 moles x (6.02 x 10^23) ≈ 1.698844 x 10^24
Therefore, there are about 1.70 x 10^24 atoms (according to the number of significant figures) in 2.822 moles of nickel.