Nutrition law of the minimum is considered an essential plant nutrient if the plant cannot complete its full life cycle without it. There are 16 essential plant soil nutrients, besides the three major elemental nutrients carbon and oxygen that are obtained by photosynthetic plants from carbon dioxide in air, and hydrogen, which is obtained from water. Plants uptake essential elements from the soil through their roots and from the air (consisting of mainly nitrogen and oxygen) through their leaves. Green plants obtain their carbohydrate supply from the carbon dioxide in the air by the process of photosynthesis. Carbon and oxygen are
Carbon dioxide stretching mode at 1388 cm which is only observed in the Raman spectrum. Carbon dioxide is soluble in water, in which it reversibly forms (carbonic acid), which is a weak acid since its ionization in water is incomplete. The hydration equilibrium constant of carbonic acid is formula_1 (at 25 °C). Hence, the majority of the carbon dioxide is not converted into carbonic acid, but remains as molecules, not affecting the pH. The relative concentrations of , and the deprotonated forms (bicarbonate) and (carbonate) depend on the pH. As shown in a Bjerrum plot, in neutral or slightly alkaline water (pH