Columbia Encyclopedia

(Encyclopedia) modem [modulator/demodulator], an external device or internal electronic circuitry used to transmit and receive digital data over a communications line normally used for analog signals. A modem attach...

(Encyclopedia) Mongolia mŏn-gōˈlēə, mŏng– [key], Asian region (c.906,000 sq mi/2,346,540 sq km), bordered roughly by Xinjiang Uygur Autonomous Region, China, on the west; the Manchurian provinces of China on...

(Encyclopedia) Sumer so͝o-mērˈēən [key]. The term Sumer is used today to designate the southern part of ancient Mesopotamia. From the earliest date of which there is any record, S Mesopotamia was occupied by a ...

(Encyclopedia) Precambrian, name of a major division of geologic time (see Geologic Timescale, tablegeologic timescale, table), from c.5 billion to 570 million years ago. It is now usually divided into the Archean a...

(Encyclopedia) aluminum ălˌyo͞omĭnˈēəm [key], metallic chemical element; symbol Al; at. no. 13; at. wt. 26.98154; m.p. 660.37℃; b.p. 2,467℃; sp. gr. 2.6989 at 20℃; valence +3. Aluminum is a silver-white...

(Encyclopedia)  CE5 Newfoundland and Labrador nyo͞oˈfənlənd, nyo͞ofənlăndˈ; lăbˈrədôrˌ [key], province (2001 pop. 512,930), 156,185 sq mi (404,519 sq km), E Canada. The province consists of the island...

(Encyclopedia) New South Wales, state (2016 pop. 7,480,228), 309,443 sq mi (801,457 sq km), SE Australia. It is bounded on the E by the Pacific Ocean. Sydney is the capital. The other principal urban centers are New...

(Encyclopedia) Permian period pûrˈmēən [key] [from Perm, Russia], sixth and last period of the Paleozoic era (see Geologic Timescale, tablegeologic timescale, table) from 250 to 290 million years ago. Many ma...

(Encyclopedia) chlorine klōrˈēn, klôrˈ– [key] [Gr.,=green], gaseous chemical element; symbol Cl; at. no. 17; interval in which at. wt. ranges 35.446–35.457; m.p. −100.98℃; b.p. −34.6℃; density 3.2 g...

(Encyclopedia) Urals or Ural Mountains, E European Russia and NW Kazakhstan, forming, together with the Ural River, the traditional boundary between Europe and Asia and separating the Russian plain from the W Siberi...