ancient Greek hero, the nephew, charioteer, and assistant of Heracles. He was the son of Iphicles, himself mortal half brother of Heracles by the same mother.
any atom or group of atoms that bears one or more positive or negative electrical charges. Positively charged ions are called cations; negatively charged ions, anions. Ions are formed by ...
in physics and chemistry, a duplex of charged particles (ordinarily charged atoms or molecules), one positive, the other negative. An ion pair, for the physicist, is the positively charged particle ...
measure of the ability of an insoluble material to undergo displacement of ions previously attached and loosely incorporated into its structure by oppositely charged ions present in the surrounding solution. ...
any of a class of chemical reactions between two substances (each consisting of positively and negatively charged species called ions) that involves an exchange of one or more ionic components.
any of a wide variety of organic compounds synthetically polymerized and containing positively or negatively charged sites that can attract an ion of opposite charge from a surrounding solution. The ...
island of the Inner Hebrides, Strathclyde region, Scotland. It is 3 miles (5 km) long by 1.5 miles (2.4 km) wide, with its highest point just under 330 feet (100 ...
missionary group of clergy and laymen within the Church of Scotland. It was founded in 1938 by George MacLeod, a parish minister in Glasgow who hoped to infuse a new ...
Romanian-born French dramatist whose one-act "antiplay" La Cantatrice chauve (1949; The Bald Soprano) inspired a revolution in dramatic techniques and helped inaugurate the Theatre of the Absurd. He was elected ...
ancient region comprising the central sector of the western coast of Anatolia (now in Turkey). It was bounded by the regions of Aeolis on the north and Caria on the ...
any member of an important eastern division of the ancient Greek people, who gave their name to a district on the western coast of Anatolia (now Turkey). The Ionian dialect ...
island group off the west coast of Greece, stretching south from the Albanian coast to the southern tip of the Peloponnese, and often called Heptanesos ("Seven Islands"). The islands are ...
school of Greek philosophers of the 6th to 5th century BC, including Thales, Anaximander, Anaximenes, Heracleitus, Anaxagoras, Diogenes of Apollonia, Archelaus, and Hippon. Although Ionia was the original centre of ...
part of the Mediterranean Sea, lying between Greece (east), Sicily (southwest), and Italy (west and northwest). Though considered by ancient authors to be part of the Adriatic Sea, the Ionian ...
. In 403 the Ionic alphabet used in the Anatolian city of Miletus was adopted for use in Athens, and by the middle of the 4th century the Ionic had ...
type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound. Such a bond forms when the valence (outermost) electrons of one atom are transferred ...
any of several Ancient Greek dialects spoken in Euboea, in the Northern Cyclades, and from approximately 1000 BC in Asiatic Ionia, where Ionian colonists from Athens founded their cities. Attic ...
in prosody, a foot of verse that consists of either two long and two short syllables (also called major ionic or a maiore) or two short and two long syllables ...
in chemistry and physics, any process by which electrically neutral atoms or molecules are converted to electrically charged atoms or molecules (ions). Ionization is one of the principal ways that ...
radiation detector used for determining the intensity of a beam of radiation or for counting individual charged particles. The device may consist of a gas-filled, cylindrical container in which an ...
in chemistry, the amount of energy required to remove an electron from an isolated atom or molecule. There is an ionization potential for each successive electron removed; the ionization potential ...
region of the Earth's atmosphere in which the number of ions, or electrically charged particles-resulting from the action of extraterrestrial (primarily solar) radiation on the neutral atoms and molecules of ...
North American Indian people of Siouan linguistic stock who in their prehistoric period migrated westward from north of the Great Lakes to the general area of the present state of ...
constituent state of the United States of America. As a north central state, it forms a bridge between the forests of the east and the grasslands of the high Prairie ...
city, seat (1839) of Johnson county, east-central Iowa, U.S., on the Iowa River, 27 miles (43 km) south of Cedar Rapids. Founded as territorial capital of Iowa in 1839, it ...
popular resort area in Dickinson county, northwestern Iowa, U.S., just south of the Minnesota border. Included are Spirit (or Big Spirit), West Okoboji, East Okoboji, and Silver lakes, all of ...
river flowing through the centre of Iowa, U.S. It rises as two headstreams, the East Branch Iowa and West Branch Iowa rivers, in the north-central part of the state; the ...
public, coeducational institution of higher learning in Ames, Iowa, U.S. The university comprises colleges of agriculture, business, design, education, engineering, family and consumer sciences, liberal arts and sciences, and veterinary ...
public, coeducational institution of higher learning in Iowa City, Iowa, U.S. It comprises colleges of business administration, dentistry, law, public health, medicine, nursing, pharmacy, education, engineering, and liberal arts and ...
city, southeastern Goias state, south central Brazil. Lying in rolling uplands between the Verissimo and Corumba rivers, tributaries of the Paranaiba, it is primarily a cattle-shipping centre that also houses ...
Russian-born U.S. chemist who was one of the first to investigate high-pressure catalytic reactions of hydrocarbons and who developed a process for manufacturing high-octane gasoline.
Athenian general known chiefly for his use of lightly armed troops (peltasts); he increased the length of their weapons and improved their mobility by reducing defensive armour.
in Greek mythology, eldest daughter of Agamemnon, king of Mycenae, and his wife Clytemnestra. Her father had to sacrifice her to the goddess Artemis in order that the Achaean fleet, ...
city, southwestern Colombia. It is located in the Andes Mountains on the banks of the Guaitara River, at 9,505 feet (2,897 metres) above sea level, and is known as the ...
Eskimo culture of northwestern Alaska, probably dating from the 2nd to the 6th century AD. A Siberian origin has been suggested, based on similarities in burial practices and ceremonialism, animal ...
city, Peninsular (West) Malaysia, on the Kinta River. Surrounded by steep hills, except to the south, it lies on a flat alluvial plain in the Kinta Valley. The name comes ...
genus of about 500 mostly warm-climate trees, shrubs, and twining and trailing herbaceous plants of the family Convolvulaceae with funnel-shaped flowers. Certain species of Ipomoea are sometimes considered as the ...
the first drug of the monoamine-oxidase inhibitor series to be introduced into medicine (1958). It was employed as an antidepressant until it was found to cause liver damage. Prior to ...
military engagement fought at Ipsus, Phrygia, in 301 BC between two camps of the "successors" (diodochoi) of Alexander the Great, part of a struggle that accelerated the dismemberment of Alexander's ...
North Sea port town and borough (district), administrative and historic county of Suffolk, England, at the head of the Orwell estuary. Ipswich prospered as a port for the export of ...
town (township), Essex county, northeastern Massachusetts, U.S. It lies along the Ipswich River (there bridged since 1764), 28 miles (45 km) north-northeast of Boston. Settled in 1633 as Agawam, it ...
ancient Egyptian sage. He perhaps served as a treasury official during the last years of Pepi II Neferkare (reigned c. 2294-c. 2200 BC) and is known only because of the ...
in Islamic music, rhythmic modes-i.e., patterns of strong, intermediate, and weak beats, separated by pauses of various lengths. A well-developed system of such modes was described by medieval theorists. Although ...
town, capital of Nunavut territory and headquarters of Baffin region, Canada. It lies at the head of Frobisher Bay, on southeastern Baffin Island. Iqaluit is the largest community in the ...
also spelled Muhammad Ikbal Indian poet and philosopher, known for his influential efforts to direct his fellow Muslims toward the establishment of a separate Muslim state, an aspiration that was ...
in the Islamic empire of the Caliphate, land granted to army officials for limited periods in lieu of a regular wage. It has sometimes been erroneously compared to the fief ...
capital of Iquique provincia and of Tarapaca region, northern Chile. It is located on a rocky peninsula in the rainless Atacama Desert, overlooking the Pacific Ocean. Its anchorage is protected ...
Amazon River port and capital of Loreto departamento, northeastern Peru. It is located about 2,300 miles (3,700 km) upstream from the Atlantic Ocean and 640 miles (1,030 km) north-northeast of ...
largest city, principal port of the Greek island of Crete, and capital of the nomos (department) of Iraklion. The city lies on the north coast just northwest of the ancient ...
a mountainous, arid, ethnically diverse country of southwestern Asia. Much of Iran consists of a central desert plateau, which is ringed on all sides by lofty mountain ranges that afford ...
international crisis (1979-81) in which militants in Iran seized 66 American citizens at the U.S. embassy in Tehran, holding 52 of them hostage for more than a year. The crisis, ...
historic region of southwestern Asia that is only roughly coterminous with modern Iran. The term Persia was used for centuries, chiefly in the West, to designate those regions where Persian ...
U.S. political scandal in which the National Security Council (NSC) became involved in secret weapons transactions and other activities that either were prohibited by the U.S. Congress or violated the ...
(1980-90), prolonged military conflict between Iran and Iraq during the 1980s. The war began on September 22, 1980, when Iraqi armed forces invaded western Iran along the countries' joint border.
subgroup of the Indo-Iranian branch of the Indo-European language family. Iranian languages are spoken in Iran, Afghanistan, Tajikistan, and parts of Iraq, Turkey, Pakistan, and scattered areas of the Caucasus ...
diverse beliefs and practices of the culturally and linguistically related group of ancient peoples who inhabited the Iranian Plateau and its borderlands, as well as areas of Central Asia from ...
city, west-central Guanajuato estado ("state"), north-central Mexico. Situated in the fertile Bajio, a valley of the central plateau, the city lies along the Irapuato River, a tributary of the Lerma ...
active volcano in the Cordillera Central, east-central Costa Rica. The highest mountain in the Cordillera Central, Irazu reaches an elevation of 11,260 feet (3,432 m). It is a popular ascent ...
town, northern Jordan. The town is built on successive Early Bronze Age settlements and was possibly the biblical Beth Arbel and the Arbila of the Decapolis, a Hellenistic league of ...
ancient town, northern Iraq. It is situated 48 miles (77 km) east of Mosul in the foothills of the mountains that rise to the east. It is a trade centre ...
