To solve for this problem, the idea of the Avogadro’s number is necessary. Remember that 1 mole of any substance contains 6.022x10^23 atoms or particles or molecules or ions.
First we have to convert the given mass of Platinum (Pt) to the number of moles Pt. We can do that by using the molar mass of platinum.
`2869.66 grams Pt * (1 mol e Pt)/(195.084 grams)`
= 14.7099 moles Pt
Then, we convert the moles of Pt to the number of Pt atoms.
`14.7099 mol es Pt * (6.022x10^23 at oms Pt)/(1 mol e Pt)`
= 8.85828x10^24 atoms of Pt