hydrogen bonding

hydrogen bonding,

the attractive force of compounds in which a hydrogen atom covalently linked to an electronegative element such as oxygen, nitrogen, or fluorine has a large degree of positive character relative to the electronegative atom, thereby causing the compound to possess a large dipole and to associate strongly with other like molecules.

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hydrogen

a chemical element, atomic number 1, atomic weight 1.00797, symbol H. See Table 6. It exists as the mass 1 isotope (protium, or light or ordinary hydrogen), mass 2 isotope (deuterium, heavy hydrogen), and mass 3 isotope (tritium).

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hydrogen bonding

weak electrostatic attraction between one electronegative atom and the hydrogen atom covalently linked to a second electronegative atom.

hydrogen breath test

detects hydrogen production as a product of bacterial fermentation of carbohydrates, an indicator of inflammatory bowel disease or carbohydrate malabsorption.

hydrogen cyanide

hydrocyanic acid.

heavy hydrogen

hydrogen having double the mass of ordinary hydrogen; deuterium.

hydrogen ion balance

see acid-base balance.

hydrogen ion concentration

the degree of concentration of hydrogen ions (the acid element) in a solution. Its symbol is pH, and expresses the degree to which a solution is acidic or alkaline. The pH range extends from 0 to 14, pH 7 being neutral. A pH of less than 7 indicates acidity, above 7 indicates alkalinity. See also acid-base balance and ph.

hydrogen peroxide

H₂O₂, used in solution as an antibacterial agent. A 3% solution foams on touching skin or mucous membrane and appears to have a mechanical cleansing action.

hydrogen peroxide-based teat dips

see teat dip.

hydrogen sulfide

an ill-smelling, colorless, poisonous gas, H₂S; much used as a chemical reagent. Hydrogen sulfide is often present in gases from oil wells and from manure vats under slatted floor barns. Poisoning of cattle causes diarrhea, dehydration, dyspnea and death in convulsions. The feces are black and the breath smells of hydrogen sulfide. Called also hydrosulfuric acid. See also manure pit gas poisoning.

hydrogen swell

defective canned meat can. Can is distended due to production of hydrogen as a result of corrosion of the can surface.