Question

How many moles is 2.80 x10^24 atoms of silicon?

Answer 1

Let x moles of silicon contains 2.8x10^24 atoms. 6.02x10^23 atoms are present in 1 mole of Si. Therefore 2.80x10^24 atoms are present in = 2.8x10^24/6.02x10^23 = 4.65 moles of Si.

Answer 2

The moles of silicon is 4.651 moles

calculation

The moles of silicon is calculated using Avogadro's constant

that is according to Avogadro's law

1 mole = 6.02 x 10^23 atoms

? moles = 2.80 x 10 ^24 atoms of silicon

by cross multiplication

= [ ( 1 mole x 2.80 x 10^24 atoms) / ( 6.02 x 10 ^23 atoms)]

= 4.651 moles