Is carbon mixed with sand a mixture

How many neutrons does a atom of cobalt have?

How many moles of air are there in a human lung with a volume of 2.4 l at stp? explain your answer

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.)