how many atoms are there in 6.02g in silicon

Question

how many atoms are there in 6.02g in silicon?

Answer 1

Divide the given mass by the atomic weight of Si to find the number of moles of Si.  Then multiply the number of moles by Avogadro's number to get the number of atoms of Si.

 

m = 6.02 g

 

W = atomic weight of Si = 28.09 g/mole [from tables]

 

A = 6.02 x 10²³ particles per mole

 

N = number of atoms

 

N = (m / W) A = [(6.02 g) / (28.09 g/mole)] (6.02 x 10²³ atoms per mole)

 

N = 1.29 x 10²³ atoms