Answer:
1.49 x 10⁻¹⁴ moles Ni
Step-by-step explanation:
To find the amount of moles in the sample, you need to multiply the amount of atoms by Avogadro's Number. This conversion is a ratio that describes how many atoms there are per every 1 mole. It is important to arrange the ratio in a way that allows for the cancellation of units (atoms should be in the denominator). The final answer should have 3 sig figs like the given value.
Avogadro's Number:
6.022 x 10²³ atoms = 1 mole
9.00 x 10⁹ atoms Ni 1 mole
--------------------------------- x -------------------------------- = 1.49 x 10⁻¹⁴ moles Ni
6.022 x 10²³ atoms