Hey there!
There are 6.022 x 10²³ atoms in one mole.
We have 5.33 x 10⁻⁵ moles.
(5.33 x 10⁻⁵) x (6.022 x 10²³)
3.21 x 10¹⁹
There are 3.21 x 10¹⁹ atoms in 5.33 x 10⁻⁵ mol C.
Hope this helps!