What is the mass of 1.56 x 1021 atoms of magnesium in grams
4 Answers

1.56×10^21 atoms x (1 mole / 6.022×10^23 atoms) x (24.3 g / mole) = 0.0629 g

First step, convert the number of atoms into moles (use where 1mole of any atom = 6.022×10^23 atoms):
1.56×10^21 atoms x (1 mol / 6.022×10^23 atoms ) = 2.59×10^3 moles
Final step, convert moles into grams (use the periodic table):
2.59×10^3 moles x (24.305g / 1mol) = 0.630 grams Mg
Good luck!

To work out the mass of 1.56 x 10^21 atoms of magnesium is grams is split into 2 parts first we have to convert the number of atoms into the number of moles and we do that using this formula
n=N/NA
n=number of moles
N=molecules of substance
NA=avogadro’s number which is 6.02 x 10^23
n=(1.56 x10^21) / (6.02 x10^23)=0.00259 mol
then to work out the mass you have to multiply the number of mole(n)
by the molar mass(M) of magnesium which is 24.3
m=n x M
m=mass
n=number of moles
M=molar mass
m=0.00259 x 24.3= 0.0629g of Mg
mass of magnesium is 0.0629g
Hope this answers your question=)

1 Mole of Mg is 24.3g.
(6.02X10^23)X24.3=1.46286X10^25
1.56X1021/1.46286X10^25=
1.09X10^22g