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anion

(Encyclopedia)anion ănˈīˌən [key], atom or group of atoms carrying a negative charge. The charge results because there are more electrons than protons in the anion. Anions can be formed from nonmetals by reduc...

Concordat of 1801

(Encyclopedia)Concordat of 1801, agreement between Napoleon Bonaparte and Pope Pius VII that reestablished the Roman Catholic Church in France. Napoleon took the initiative in negotiating this agreement; he recogni...

sediment

(Encyclopedia)sediment, mineral or organic particles that are deposited by the action of wind, water, or glacial ice. These sediments can eventually form sedimentary rocks (see rock). Sediments form sedimentary ...

phospholipid

(Encyclopedia)phospholipid fŏsˌfōlĭpˈĭd [key], lipid that in its simplest form is composed of glycerol bonded to two fatty acids and a phosphate group. The resulting compound called phosphatidic acid contains...

ammonium chloride

(Encyclopedia)ammonium chloride əmōˈnēəm klôrˈīd [key], chemical compound, NH4Cl, a white or colorless, odorless, water-soluble, cubic crystalline salt with a biting taste, commonly known as sal ammoniac. I...

silica gel

(Encyclopedia)silica gel, chemical compound. It is a colloidal form of silica, and usually resembles coarse white sand. It may be prepared by partial dehydration of metasilicic acid, H2SiO3. Because it has many tin...

septic tank

(Encyclopedia)septic tank, underground sedimentation tank in which sewage is retained for a short period while it is decomposed and purified by bacterial action. The organic matter in the sewage settles to the bott...

barberry

(Encyclopedia)CE5 Barberry, Berberis vulgaris barberry bärˈbĕrˌē [key], common name for the family Berberidaceae, and specifically for the spiny barberries (Berberis species). The family includes perennial...

ginger

(Encyclopedia)ginger, common name for members of the Zingiberaceae, a family of tropical and subtropical perennial herbs, chiefly of Indomalaysia. The aromatic oils of many are used in making condiments, perfumes, ...

anise

(Encyclopedia)anise ănˈĭs [key], annual plant (Pimpinella anisum) of the family Umbelliferae (parsley family), native to the Mediterranean region but long cultivated elsewhere for its aromatic and medicinal qual...