| hydrogen |
a chemical element that contains one proton in each nucleus and that occurs naturally in many compounds such as water, acids, petroleum hydrocarbons, and carbohydrates, and in pure form as a highly flammable, lighter-than-air gas used in many industrial applications, such as the hydrogenation of fats and oils. (symbol: H) (Cf. deuterium, protium, tritium.) |
| hydrogenate |
to treat or cause to combine with hydrogen. |
| hydrogen bomb |
an extremely powerful bomb whose destructive energy comes from the fusion of hydrogen nuclei under intense heat and pressure, forming helium nuclei. |
| hydrogen ion |
the positive ion of a hydrogen atom whose electron has been removed, as in acids. |
| hydrogen peroxide |
an unstable compound of hydrogen and oxygen whose water solution is used mostly as an antiseptic or bleach. |
| hydrogen sulfide |
a poisonous, colorless gas that has the odor of rotten eggs and is used mostly in chemical manufacturing and metallurgy. |
| hydrography |
the study or science of describing or mapping the earth's bodies of water, esp. in relation to navigational or commercial uses. |
| hydroid |
characteristic of the asexual hydrozoan polyp. [2 definitions] |
| hydrologic |
pertaining to the circulation, distribution, or quality of the waters of the earth, or to the field of hydrology. |
| hydrological |
of or pertaining to the study of the earth's waters. |
| hydrology |
the scientific study of the distribution, circulation, and quality of the waters of the earth. |
| hydrolysis |
the decomposing of a chemical compound by combining it with water or the elements of water. |
| hydrolyte |
a substance that has gone through the process of hydrolysis. |
| hydrolyze |
to subject to or undergo hydrolysis. |
| hydrometer |
an instrument, usu. a sealed glass tube containing a graduated scale and weighted at one end, used to measure the specific gravity of liquids. |
| hydropathy |
the treatment of disease by the use of water, as by drinking or external application. (Cf. hydrotherapy.) |
| hydrophilic |
of or pertaining to a substance that has a strong affinity for water. |
| hydrophobia |
abnormal fear of water. [2 definitions] |
| hydrophobic |
having a fear of water. [2 definitions] |
| hydrophyte |
a plant that grows in water alone or in esp. wet ground. |
| hydroplane |
a light, fast motorboat that at high speeds skims the water with only the rear part of the hull touching the surface. [5 definitions] |