How many atoms are in 12 moles of iron?

Afamily is one another name for a group on the table of elements.

Silver tarnishes as silver metal reacts with hydrogen sulfide, h2s, in the air. in this reaction, dark silver sulfide, au2s, covers the surface of silver. when silver is polished, this coating of silver sulfide can be removed from the surface. this makes the silver shiny again. enter the coefficients that balance the tarnishing reaction equation. (type 1 for no coefficient.)

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.