Convert 1.65 × 1024 atoms of carbon to moles of carbon.

The number of moles in a substance indicates the amount of the substance that contains the same number of particles as 12 g of the Carbon-12 isotope [or equivalent to 6.02 × 10²³] (which is used as a standard in the world of moles).

Now,

          if     6.02 × 10²³ atoms are found in 1 mole of C
   then let  1.65 × 10²⁴ atoms are found in     x

⇒     x  =    (1.65 × 10²⁴)  ÷  (6.02 × 10²³)

            =  2.7409 mol


A sample of 1.65 × 10²⁴ atoms of Carbon (C) would contain ~ 2.74 mol