Some Basic Concepts of Chemistry Part 1

Number of moles of Fe in 558.5‌gm of Fe is
=‌

558.5

55.85

=10
∴ Number moles of Fe in 558.5‌gm‌Fe is =10
Since here Fe is monoatomic then no. of atoms in 10 moles Fe is
⇒10×1×NA
⇒10NA
For Option (A) Atomic Mass of Carbon is 12g then no. of moles in 60g Carbon is
⇒‌

60

12

=5
Here Carbon is also monoatomic then no. of atoms in 5 moles of Carbon
⇒5×1×NA
⇒5NA
Now we can clearly see 10 is twice of 5 , so option (A) is correct.