Answer:
[tex]\large \boxed {2.8 \times 10^{23}\text{ atoms Ar}}[/tex]
Explanation:
[tex]\text{Atoms of Ar} = \text{0.47 mol Ar} \times \dfrac{ 6.022 \times 10^{23}\text{ atoms Ar}}{\text{1 mol Ar}}\\\\= \large \boxed {\mathbf{2.8 \times 10^{23}}\textbf{ atoms Ar}}[/tex]