Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks as the minerals calcite and aragonite (most notably as limestone, which contains both of those minerals) and is the main component of pearls and the shells of marine organisms, snails, and eggs.
An ordinary breath for a 70-kg adult is about 500ml of air. We call this the tidal volume. Since oxygen is 21% by volume of air, then the volume of oxygen inhaled is about 105ml. The density of pure oxygen at sea level is 1.43kg per cubic metre.
Yes. Most untrained people can comfortably hold their breath for 30 seconds before gasping. That threshold has little to do with oxygenâyour body has plenty of that in reserve. The more dangerous problem is the buildup of carbon dioxide, which acidifies the blood.