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periodic table

(Encyclopedia)CE5 periodic table, chart of the elements arranged according to the periodic law discovered by Dmitri I. Mendeleev and revised by Henry G. J. Moseley. In the periodic table the elements are arrange...

rock

(Encyclopedia)rock, aggregation of solid matter composed of one or more of the minerals forming the earth's crust. The scientific study of rocks is called petrology. Rocks are commonly divided, according to their o...

wool

(Encyclopedia)wool, fiber made from the fleece of the domestic sheep. In the United States, by the Wool Products Labeling Act of 1939, the term wool may be applied only to fabrics made entirely of new wool; t...

submarine

(Encyclopedia)submarine, naval craft capable of operating for an extended period of time underwater. Submarines are almost always warships, although a few are used for scientific, business, or other purposes (see a...

space medicine

(Encyclopedia)space medicine, study of the medical and biological effects of space travel on living organisms. The principal aim is to discover how well and for how long humans can withstand the extreme conditions ...

petroleum

(Encyclopedia)petroleum, oily, flammable liquid that occurs naturally in deposits, usually beneath the surface of the earth; it is also called crude oil. It consists principally of a mixture of hydrocarbons, with t...

forestry

(Encyclopedia)forestry, the management of forest lands for wood, water, wildlife, forage, and recreation. Because the major economic importance of the forest lies in wood and wood products, forestry has been chiefl...

molecule

(Encyclopedia)molecule mŏlˈəkyo͞ol [key] [New Lat.,=little mass], smallest particle of a compound that has all the chemical properties of that compound. A single atom is usually not referred to as a molecule, a...

battery, electric

(Encyclopedia)CE5 Lead storage cell: At the lead-dioxide electrode, electrons from the circuit combine with lead dioxide and sulfuric acid to form lead sulfate and water. At the spongy-lead electrode, lead react...

plate tectonics

(Encyclopedia)CE5 Plate tectonics: Map of the world showing major plates and plate boundaries CE5 Plate tectonics: Schematic model of the oceanic crust, showing the three types of plate boundaries plate tect...