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transuranium elements

(Encyclopedia)transuranium elements, in chemistry, radioactive elements with atomic numbers greater than that of uranium (at. no. 92). All the transuranium elements of the actinide series were discovered as synthet...

spectrum

(Encyclopedia)CE5 Dispersion of white light by a triangular prism spectrum, arrangement or display of light or other form of radiation separated according to wavelength, frequency, energy, or some other propert...

MacArthur, Douglas

(Encyclopedia)MacArthur, Douglas, 1880–1964, American general, b. Little Rock, Ark.; son of Arthur MacArthur. At the beginning (1950) of the Korean War he was appointed commander of UN military forces in South ...

designer drug

(Encyclopedia)designer drug, chemical substance synthesized in a laboratory that is intended to have effects similar to those of a drug that is a controlled substance, such as methamphetamine, marijuana, LSD, or an...

radiation sickness

(Encyclopedia)radiation sickness, harmful effect produced on body tissues by exposure to radioactive substances. The biological action of radiation is not fully understood, but it is believed that a disturbance in ...

solid-state physics

(Encyclopedia)solid-state physics, study of the properties of bulk matter rather than those of the individual particles that compose it. Solid-state physics is concerned with the properties exhibited by atoms and m...

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...

statistical mechanics

(Encyclopedia)statistical mechanics, quantitative study of systems consisting of a large number of interacting elements, such as the atoms or molecules of a solid, liquid, or gas, or the individual quanta of light ...

Thatcher, Margaret Hilda Roberts Thatcher, Baroness

(Encyclopedia)Thatcher, Margaret Hilda Roberts Thatcher, Baroness, 1925–2013, British political leader. Great Britain's first woman prime minister, nicknamed the “Iron Lady” for her uncompromising political s...

magnetic resonance

(Encyclopedia)magnetic resonance, in physics and chemistry, phenomenon produced by simultaneously applying a steady magnetic field and electromagnetic radiation (usually radio waves) to a sample of atoms and then a...