The mass of an individual atom of chromium is 52.00 amu.

Question

ow many atoms would weigh a total of 0.00001461 g of this element if the mass of 1 amu is 1.6605x10-24 g?

Answer 1

N = number of atoms

 

m = mass of chromium atom = 52 amu = 52 * 1.6605 x 10^-24 g = 8.6346 x 10^-23 g

 

M = total mass of N atoms = 1.461 x 10^-5 g

 

N = M/m = (1.461 x 10^-5 g) / (8.6346 x 10^-23 g) = 1.692 x 10^17 atoms