What can the size and shape of a sand dune tell you about how it was formed?

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.)

How would the number of moles (n) of o2 change if the atmospheric pressure doubled but all other variables stayed the same

Amixture that has two or more substances that are spread out evenly is called a. compound b. heterogeneous c. substance d. homogeneous