Answer:
1.69g
Explanation:
To solve the problem you need to know the Avogadro´s number and the molar mass of the Platinum.
The Avogadro´s number is [tex]6.022*10^{23}\frac{atoms}{mol}[/tex]. For the platinum it means that there are [tex]6.022*10^{23}\frac{atoms}{mol}[/tex] atoms of platinum for each mol.
And the molar mass for the platinum is [tex]195.084\frac{g}{mol}[/tex], that is the mass in grams of each mol of platinum.
So, with this information we can solve the problem as follows:
[tex]5.22*10^{21}atomsofPt*\frac{1molofPt}{6.022*10^{23}atomsofPt}*\frac{195.084g}{1molofPt}=1.69g[/tex] of Pt