Respuesta :
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.
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