Answer:
4.50
×
10
22
gold atoms
6.022
×
10
23
gold atoms per mole
×
196.97
⋅
g
⋅
m
o
l
−
1
=
?
?
g
Explanation:
One mole of gold has a mass of
196.97
⋅
g
⋅
m
o
l
−
1
. By definition there are
Avogadro's number
of gold atoms that constitute this mass, i.e.
N
A
=
6.022
×
10
23
.
So we take the quotient to get an answer in moles, and mulitply this by the molar mass to get the mass:
4.50
×
10
22
gold atoms
6.022
×
10
23
gold atoms per mole
×
196.97
⋅
g
⋅
m
o
l
−
1
=
?
?
