For brainiest:):):):):):):):)

Which is the layer underground where all empty spaces are filled with a combination of air and water ?

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.)

Ineed to find the answer of this question because i dont understand it