Weegy: How many chemical reactions are possible regarding the formation of carbonic acid and the dissolving of calcite?
D. 2 User: Which gas is a source of natural groundwater pollution?
A. Carbon B. Hydrogen C. Radon D. Oxygen Weegy: Radon gas is a source of natural groundwater pollution. The answer is letter D. Radon gas is a radioactive product of the decay of naturally occurring uranium in the Earth's crust. [ Groundwater entering a ... (More)