Question

4) How many atoms and molecules of sulphur are present in 64 g of s8​

Answer 1

6.02 × 10²³ × 0.25 = 1.505 × 10²³ atoms

Answer 2

Atomic mass of S = 32g

now Atomic mass of S8 = 32×8 = 256g

now 256g =how many moles?

⇒256/32 = 8 moles                        (Given weight /Gram Molecular Weight )

now, 1mole = avogadro number of molecules

 therefore 8 moles = 8× avgadro number

⇒avogadro number = 6.022×10^23

⇒8× (6.022×10^23)= 48.176×10^23 molecules

now 1 molecule of s8 has 8 atoms...now you calculate it for above number of molecules by cross multiplication....   :)