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lithium

(Encyclopedia)lithium lĭthˈēəm [key] [Gr.,=stone], metallic chemical element; symbol Li; at. no. 3; interval in which at. wt. ranges 6.938–6.997; m.p. about 180.54℃; b.p. about 1,342℃; sp. gr. .534 at 20�...

water, desalination of

(Encyclopedia)water, desalination of, process of removing soluble salts from water to render it suitable for drinking, irrigation, or industrial uses. The principal methods used for desalination include distillatio...

aurora borealis

(Encyclopedia)aurora borealis ôstrāˈlĭs [key], luminous display of various forms and colors seen in the night sky. The aurora borealis of the Northern Hemisphere is often called the northern lights, and the aur...

neutron

(Encyclopedia)neutron, uncharged elementary particle of slightly greater mass than the proton. It was discovered by James Chadwick in 1932. The stable isotopes of all elements except hydrogen and helium contain a n...

mucopolysaccharide

(Encyclopedia)mucopolysaccharide myo͞oˌkəpŏlēsăkˈərīd [key], class of polysaccharide molecules, also known as glycosaminoglycans, composed of amino-sugars chemically linked into repeating units that give a...

technetium

(Encyclopedia)technetium tĕknēˈshēəm [key] [Gr. technetos=artificial], artificially produced radioactive chemical element; symbol Tc; at. no. 43; mass no. of most stable isotope 98; m.p. 2,200℃; b.p. 4,877�...

alkaloid

(Encyclopedia)alkaloid, any of a class of organic compounds composed of carbon, hydrogen, nitrogen, and usually oxygen that are often derived from plants. Although the name means alkalilike, some alkaloids do not e...

alkane

(Encyclopedia)CE5 Alkanes alkane ălˈkān [key], any of a group of aliphatic hydrocarbons whose molecules contain only single bonds (see chemical bond). Alkanes have the general chemical formula CnH2n+2. An al...

essential oils

(Encyclopedia)essential oils, volatile oils that occur in plants and in general give to the plants their characteristic odors, flavors, or other such properties. Essential oils are found in various parts of the pla...

proton

(Encyclopedia)proton, elementary particle having a single positive electrical charge and constituting the nucleus of the ordinary hydrogen atom. The positive charge of the nucleus of any atom is due to its protons....