Answer:
~4,317.5 moles of Silicon
Explanation:
Using Avogadro's contant we know that:
1mole = 6.022 x 10^23 atoms
So,to calculate the number of moles in 2.60 x 10^27 atoms of Silicon:
=(2.60 x 10^27 x 1)/(6.022 x 10^23)
~4,317.5 moles of Silicon
Hope it helps:)