Natural monopolies are O food products with a monopoly market
O products that one supplier can produce most efficiently
O products where the government chooses a company to produce it
O markets for items where consumers have considerable price control

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds