When 4.50 l of hydrogen gas react with an excess of nitrogen gas at standard temperature and pressure, how many liters of ammonia gas will be produced?

Areaction in which products can react to re-form reactants is

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.

Which example is a mechanical wave?     a. microwave    b. radio wave    c. water wave    d. ultraviolet light