Answer
1.60×$10^{-16}$g
Work Step by Step
Recall:
Number of moles= Number of molecules÷ Avogadro number.
Then, number of moles= $\frac{6.00×10^{6}}{6.022×10^{23}}$= $9.96×10^{-18}$mol.
Mass in grams = Number of moles×Molar mass = $9.96×10^{-18}mol×16.04g/mol$= $1.60×10^{-16}g$