CO2 is an important trace gas in Earth's atmosphere. It is an integral part of the carbon cycle, a biogeochemical cycle in which carbon is exchanged between the Earth's oceans, soil, rocks and the biosphere. Plants and other photoautotrophs use solar energy to produce carbohydrate from atmospheric carbon dioxide and water by photosynthesis. Almost all other organisms depend on carbohydrate derived from photosynthesis as their primary source of energy and carbon compounds.
<span>Oil is less dense than water so it floats, that is also why you have to shake real well any oil- based salad dressings (Italian and vinegarettes) before using.</span>
