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rhenium

(Encyclopedia)rhenium rēˈnēəm [key], metallic chemical element; symbol Re; at. no. 75; at. wt. 186.207; m.p. about 3,180℃; b.p. about 5,625℃; sp. gr. 21.02 at 20℃; valence −1, +2, +3, +4, +5, +6, or +7....

neodymium

(Encyclopedia)neodymium nēˌōdĭmˈēəm [key], metallic chemical element; symbol Nd; at. no. 60; at. wt. 144.242; m.p. about 1,021℃; b.p. about 3,068℃; sp. gr. 7.004 at 20℃; valence +3. Neodymium is a lust...

solid

(Encyclopedia)solid, one of the three commonly recognized states in which matter occurs, i.e., that state, as distinguished from liquid and gas, in which a substance has both a definite shape and a definite volume....

atomic weight

(Encyclopedia)atomic weight, mean (weighted average) of the masses of all the naturally occurring isotopes of a chemical element, as contrasted with atomic mass, which is the mass of any individual isotope. Althoug...

desert

(Encyclopedia)desert, arid region, usually partly covered by sand, having scanty vegetation or sometimes almost none, and capable of supporting only a limited and specially adapted animal population. The so-called ...

variable star

(Encyclopedia)variable star, star that varies, either periodically or irregularly, in the intensity of the light it emits. Other physical changes are usually correlated with the fluctuations in brightness, such as ...

weather

(Encyclopedia)weather, state of the atmosphere at a given time and place with regard to temperature, air pressure (see barometer), wind, humidity, cloudiness, and precipitation. The term weather is restricted to co...

lanthanum

(Encyclopedia)lanthanum lănˈthənəm [key] [Gr.,=to lie hidden], metallic chemical element; symbol La; at. no. 57; at. wt. 138.90547; m.p. about 920℃; b.p. about 3,460℃; sp. gr. 6.19 at 25℃; valence +3. Lan...

mushroom

(Encyclopedia)CE5 The poisonous mushroom Amanita mushroom, type of basidium fungus characterized by spore-bearing gills on the underside of the umbrella- or cone-shaped cap. The name toadstool is popularly rese...

goatsucker

(Encyclopedia)goatsucker, common name for nocturnal or crepuscular birds of the order Caprimulgiformes, which includes the frogmouth, the oilbird, potoos, and nightjars. Goatsuckers are medium in size and are found...