X The letter X is the twenty-fourth letter in the Latin alphabet. Its name in English language is ex . In phonetics, x is the International Phonetic Alphabet and X-SAMPA symbol for the voiceless velar fricative .
	X-ray X-rays are a form of electromagnetic radiation with a wavelength in the range of 10 to 0.01 nanometres, corresponding to frequency in the range 30 to 30 000 Hertz . X-rays are primarily used for diagnostic radiography and X-ray crystallography.
	X-ray machine An X-ray machine is a machine used to produce X-rays via X-ray tubes. These machines are designed to generate artificial X-ray photons on demand.
	X-ray tube An X-Ray tube is a vacuum tube designed to produce man made X-Ray photons on demand. X-ray tubes are part of X-ray machines. By convention, photons of similar, and sometimes higher energy, but emanating from natural sources are called gamma rays. X-Rays photons are part of the electromagnetic spectrum, historically named as extending from radio waves to microwaves, infrared, visible light, ultraviolet and gamma rays.
	Xanthate Xanthates are the salts and esters of a xanthic acid, ROC(=S)SH or O-esters of dithiocarbonic acid where R is any organic residue. The ethyl ester CH3CH2OC(=S)SH is also the parent compound xanthic acid. Many xanthates have a yellow colour, which gives the compound its name derived from xanthous, meaning yellow.
	Xanthine Xanthines are a group of alkaloids that are commonly used for their effects as mild stimulants and as bronchodilators, notably in treating the symptoms of asthma. Their effects, however, are widespread and their therapeutic range is narrow and so they are not the drug of choice in asthma treatment.
	Xanthorrhoeaceae Xanthorrhoeaceae is the botanical name of a family of flowering plants. Such a family has been recognized by most taxonomists, but the of the family has varied wildly. The APG II system also recognizes this family and places the family in the order Asparagales, in the clade monocots and allows two options:
	Xanthosoma Xanthosoma is a genus of about 50 species of tropical and sub-tropical arums in the flowering plant family, Araceae, all native to tropical Americas. Several species are grown for their starchy corms, an important root vegetable of tropical regions, known variously as malanga, new cocoyam, tannia, tannier, yauta, macabo, taioba , and ‘ape.
	Xenarthra The superorder Xenarthra is a group of placental mammals , extant today only in the Americas. The origins of the order can be traced back as far as the early Tertiary . The presence of these animals in North America is explained by the Great American Interchange. It includes the anteaters, sloths, and armadillos.
	Xenolith A xenolith is a rock fragment which becomes enveloped in a larger rock during the latter's development and hardening. In geology, the term xenolith is almost exclusively used to describe inclusions in igneous rock during magma emplacement and eruption. Xenoliths may be engulfed along the margins of a magma chamber, torn loose from the walls of an erupting lava conduit or explosive diatreme, or picked up along the base of a flowing lava on Earth's surface.
	Xenon Xenon is a chemical element in the periodic table that has the symbol Xe and atomic number 54. A colorless, heavy, odorless noble gas, xenon occurs in the earth's atmosphere in trace amounts and was part of the first noble gas compound synthesized. table characteristics
	Xenophon Xenophon , son of Gryllus, of the deme Erchia of Athens, was a soldier, mercenary and an admirer of Socrates and is known for his writings on the history of 4th century BC, the sayings of Socrates, and the life of Greece.
	Xenopus Xenopus are a genus of carnivorous frog native to Africa. There are 15 species in the Xenopus genus, all aquatic with unwebbed fingers and fully webbed feet, with claws on three toes. The best-known species belonging to this genus is Xenopus laevis, which is commonly studied as a model organism.
	Xenosauridae Classification Family Xenosauridae *Subfamily Shinisaurinae **Genus Shinisaurus *Subfamily Xenosaurinae **Genus Xenosaurus Category:Lizards Category:Xenosaurids de:Hckerechsen fr:Xenosauridae nl:Knobbelhagedissen pt:Xenosauridae
	Xenotime Xenotime is a rare yttrium phosphate mineral whose chemical formula is YPO4. It forms a solid solution series with chernovite-(Y) and therefore may contain trace impurities of arsenic, as well as silicon dioxide and calcium; the rare earths dysprosium, erbium, terbium, thorium, uranium, ytterbium; and zirconium: Due to uranium and thorium impurities, some xenotime specimens may be weakly to strongly radioactive.
	Xeranthemum Xeranthemum is a flower of the genus Xeranthemum native to Southern Europe. It has silvery flower heads with purplish tubular flowers.
	Xerography Xerography is a photocopying technique developed by Chester Carlson in 1938 and patented on October 6, 1942. He received for his invention. The name xerography came from the radicals xeros and graphos, because there are no liquid chemicals involved in the process, unlike earlier reproduction techniques like cyanotype.
	Xerophile Xerophiles are extremophile organisms that can cell growth and biological reproduction in conditions with a low availability of water, also known as water activity. Water activity is a measure of the amount of water within a Wiktionary:substrate that an organism can use to support growth.
	Xerophyllum tenax Xerophyllum tenax is a grasslike perennial in the family Melanthiaceae, closely related to Liliaceae. It is known by several common names, including bear grass, squaw grass, soap grass, quip-quip, and Indian basket grass. It can grow to 15-150 cm in height and grows in bunches with the leaves wrapped around and extending from a small stem at ground level.
	Xerox Xerox Corporation is an United States document management company, which manufactures and sells a range of color and black-and-white Computer printer, multifunction systems, photo copiers, digital production printing presses, and related consulting services and supplies.
	Xhosa The Xhosa people are a group of peoples of Bantu origins living in south-east South Africa, and in the last two centuries throughout the southern and central southern parts of the country.
	Xi Xi is the 14th letter of the Greek alphabet. It is pronounced zye by English language speakers, but ksee by modern Greek language. The modern Greek pronunciation has also become fairly common among mathematicians, even speaking in English. In the system of Greek numerals, it has a value of 60.
	Xinjiang Xinjiang, full name Xinjiang Uyghur Autonomous Region, is an autonomous region of China of the People's Republic of China. It is a large, sparsely populated area which takes up about one sixth of the country's territory. Xinjiang borders the Tibet Autonomous Region to the south and Qinghai and Gansu provinces to the southeast, Mongolia to the east, Russia to the north, and Kazakhstan, Kyrgyzstan, Tajikistan, Afghanistan, and the Pakistan- and India-controlled part
	Xiphosura Xiphosura is a class (biology) of marine Chelicerata which includes a large number of extinct lineages and only four recent species in the family Limulidae, which include the horseshoe crabs. The group has hardly changed in millions of years; the modern horseshoe crabs look almost identical to prehistoric genera such as the Jurassic Mesolimulus, and are considered to be living fossils.
	Xmas This article is about the spelling XMAS which is often used as an abbreviation for "Christmas"."Xmas" and "X-mas" are common abbreviations of the word "Christmas". They are sometimes pronounced "eksmas", but they, and variants such as "Xtemass", originated as handwriting abbreviations for the pronunciation "Christmas".
	XOR gate The XOR gate (sometimes EOR gate) is a digital logic gate that implements exclusive disjunction - it behaves according to the truth table to the right. A HIGH output (1) results if one, and only one, of the inputs to the gate is HIGH (1). If both inputs are LOW (0) or both are HIGH (1), a LOW output (0) results.
	XTC XTC are an influential new wave music band from Swindon, England.
	Xv xv is a shareware program written by John Bradley to display and modify digital images under the X Window System. While initially popular, it has become dated and has not been updated since December 1994. Bradley was unable to negotiate the LZW licence necessary for decoding the then-popular GIF format.
	Xylem In vascular plants, xylem is one of the two types of transport tissue in plants, phloem being the other one. The word xylem is derived from classical Greek language ?????, "wood", and indeed the best known xylem tissue is wood, though it is found throughout the plant.
	Xylene The term xylenes refers to a group of 3 benzene derivatives which encompasses ortho-, meta-, and para- isomers of dimethyl benzene. The o-, m- and p- isomers specify to which carbon atoms the two methyl groups are attached. Counting the carbon atoms from one of the ring carbons bonded to a methyl group, and counting towards the second ring carbon bonded to a methyl group, the o- isomer has the IUPAC name of 1,2-dimethylbenzene.
	Xylomelum Xylomelum is a genus of five species in the plant family Proteaceae. They are native to Australia, growing in the form of tall shrubs and trees. The genus includes at least two species with the common name woody pear, Xylomelum pyriforme in the eastern states of Australia, and Xylomelum occidentale in Western Australia.
	Xylophone The xylophone is a musical instrument in the percussion instrument family which probably originated in Indonesia . It consists of wooden bars of various lengths that are struck by a plastic, wooden, or rubber drum stick#Mallets. Each bar is tuned to a specific pitch of the chromatic scale.
	Xylose Xylose is an aldopentose — a monosaccharide containing five carbon atoms and including an aldehyde functional group. It has chemical formula 5105. Xylose is found in the embryos of most edible plants. It is said to be one of eight sugars which are essential for human nutrition, the others being galactose, glucose, mannose, N-acetylglucosamine, N-acetylgalactosamine, fucose, and sialic acid.
	Xylosma Xylosma is a genus of between 85-100 species of evergreen shrubs and trees in the family Salicaceae. The genus is predominantly native to the tropics, from the Caribbean, Central America, northern South America, the Pacific Islands, southern Asia and northern Australasia, but with two species, X.
	Xyridaceae Xyridaceae is the botanical name of a family of flowering plants. Such a family has been recognized by many taxonomists and is known as the Yellow-eyed-grass Family. The APG II system, of 2003, also recognizes this family, and assigns it to the order Poales in the clade commelinids, in the monocots.
	Xyris Xyris is the botanical name of a genus of flowering plants. The genus counts over two hundred fifty species, with the center of distribution in the Guinana's. The Leaf are mostly distichous, linear, flat and thin or round with a conspicuous sheath at the base. They are arranged in a basal aggregation.