What is the concentration (in M) of the chloride ion when 19.7 mL of a 0.587 M solution of barium chloride is combined with 18.6 mL of a 0.549 M solution of aluminum chloride

if you mean hydrogen and oxygen then water is the product

it means there are 3 atoms of oxygen

because natural gas is colorless, odorless, and tasteless, distributors add mercaptan (a chemical that smells like sulfur) to give natural gas a distinct unpleasant odor (it smells like rotten eggs). they locate the types of rock that are likely to contain natural gas deposits.