Answer: 7.21 × 10⁻⁷ g
Explanation:
Since we are starting from the number of atoms of Nickel, we need to know two sets of formulas:
mass = moles × molar mass
moles = atoms ÷ Avogadro's Number
⇒ mass = (atoms ÷ Avogadro's Number) × molar mass
mass = [(7.4 × 10¹⁵ atoms) ÷ (6.022 × 10²³ atoms/mole)] × (58.69 g/mol)
= 7.21 × 10⁻⁷ g
The mass of 7.4 x 10^15 atoms of nickel (Ni) is 7.21 × 10⁻⁷ g.
