The reactants in a reaction are the elements or compounds doing the actual reacting. In this word problem, you can identify this with the keyword reacts. It states, "Magnesium reacts with hydrochloric acid." Thus, you can also infer that the products are what are produced.
Coal produces more pollution than any other energy source. While coal produces just 44% of U.S. electricity, it accounts for 80% of power plant carbon emissions. Burning coal leads to soot, smog, acid rain, global warming, and carbon emissions.
