Answer :
Explanation:
The mass number of an element is a weighted average of all the isotopes of that element.
If Au has only one isotope then the atomic weight of that isotope matches the mass number.
Au-197 ==> mass number 197
Mass of one atom=mass number 197 amu
Mass of one mol of atoms:
[tex]m=197 amu*1.66054*10^{-24}g/amu*6.022*10^{23}[/tex]
[tex]m=196.97 g[/tex]
The mass of one Au atom is 196.97 amu from periodic table and the mass of Avogadro's number of Au atoms is 196.97 g due to this is the mass of one mole of gold
