First, we want to convert grams of sulfur into moles of sulfur

20 g S

(1 mole S) / (32.07 g S)

= 0.624 moles S


Now, we'll convert moles S to atoms S

0.624 moles S

(6.022 x 10²³ atoms) / (1 mole S)

= 3.758 x 10²³ atoms S


Next, we'll set atoms of S equal to atoms of C

3.758 x 10²³ atoms S = 3.758 x 10²³ atoms C


and convert atoms of C to moles of C

3.758 x 10²³ atoms C

(1 mole C) / (6.022 x 10²³ atoms C)

= 0.624 moles C


and finally, moles of C to grams of C

0.624 moles C

(12.01 g C) / (1 mole C )

= 7.494 g C


7.5 grams C contain the same amount of atoms as 20 g S

if we want to consider sig figs, the answer would be 8 g C