How many moles are in #9.04*10^26# atoms of zinc?
The problem basically wants you to find a way to convert between the number of atoms present in the sample and the number of moles they are equivalent to.
To convert between atoms and moles we use something called Avogadro's constant, which basically acts as the definition of a mole.
More specifically, in order to have one mole of an element you need
In your case, you will have
#9.04 * 10^(26)color(red)(cancel(color(black)("atoms Zn"))) * overbrace("1 mole Zn"/(6.022 * 10^(23)color(red)(cancel(color(black)("atoms Zn")))))^(color(blue)("Avogadro's constant"))#
#= color(green)(bar(ul(|color(white)(a/a)color(black)(1.50 * 10^3"moles Zn")color(white)(a/a)|)))#
The answer is rounded to three sig figs.