Please give a math to prove the answer

State the formula for density in words and mathematical symbols

What is the number of moles of chemical units represented by 9.03x10^24? and how do i show work? (dumb it down )

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.)