N is the fourteenth letter of the English alphabet. N or n may also refer to:

Mathematics

\mathbb

or N, the set of

natural number In mathematics, the natural numbers are the numbers 0, 1, 2, 3, and so on, possibly excluding 0. Some start counting with 0, defining the natural numbers as the non-negative integers , while others start with 1, defining them as the positive in ...

s * N, the

field norm In mathematics, the (field) norm is a particular mapping defined in field theory, which maps elements of a larger field into a subfield. Formal definition Let ''K'' be a field and ''L'' a finite extension (and hence an algebraic extension) o ...

* N for ''nullae'', a rare Roman numeral for zero * n, the size of a

statistical sample In this statistics, quality assurance, and survey methodology, sampling is the selection of a subset or a statistical sample (termed sample for short) of individuals from within a statistical population to estimate characteristics of the whole ...

Science

* ATC code N ''Nervous system'', a section of the Anatomical Therapeutic Chemical Classification System *

Haplogroup N (mtDNA) Haplogroup N is a human mitochondrial DNA (mtDNA) clade. A macrohaplogroup, its descendant lineages are distributed across many continents. Like its sibling macrohaplogroup M, macrohaplogroup N is a descendant of the haplogroup L3. All mtDNA h ...

, a human mitochondrial DNA haplogroup *

Haplogroup N (Y-DNA) Haplogroup N (M231) is a Y-chromosome DNA haplogroup defined by the presence of the single-nucleotide polymorphism (SNP) marker M231. It is most commonly found in males originating from northern Eurasia. It also has been observed at lower fr ...

, a human Y-chromosome DNA haplogroup * N band, an atmospheric transmission window in the mid-infrared centred on 10 micrometres *

N ray N-rays (or N rays) were a hypothesized form of radiation described by :French physicists, French physicist Prosper-René Blondlot in 1903. They were initially confirmed by others, but subsequently found to be illusory. Background The N-ray a ...

, a hypothesized form of radiation, found to be illusory *N., abbreviation of the Latin word ''nervus'' meaning

nerve A nerve is an enclosed, cable-like bundle of nerve fibers (called axons). Nerves have historically been considered the basic units of the peripheral nervous system. A nerve provides a common pathway for the Electrochemistry, electrochemical nerv ...

, used in anatomy, e.g. N. vagus

Quantities and units

* N for

Newton (unit) The newton (symbol: N) is the unit of force in the International System of Units (SI). Expressed in terms of SI base units, it is 1 kg⋅m/s2, the force that accelerates a mass of one kilogram at one metre per second squared. The unit ...

, the SI derived unit of force * N or

F_n

, a

normal force In mechanics, the normal force F_n is the component of a contact force that is perpendicular to the surface that an object contacts. In this instance '' normal'' is used in the geometric sense and means perpendicular, as opposed to the meanin ...

in mechanics *

Nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

, symbol N, a chemical element * N or Asn, the symbol for the common natural amino acid

asparagine Asparagine (symbol Asn or N) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH form under biological conditions), an α-carboxylic acid group (which is in the depro ...

* N, the

Normality (chemistry) In chemistry, the equivalent concentration or normality () of a solution is defined as the molar concentration divided by an equivalence factor or -factor : N = \frac Definition Normality is defined as the number of gram or mole equivale ...

or chemical concentration of a solution * ''N'', the

neutron number The neutron number (symbol ''N'') is the number of neutrons in a nuclide. Atomic number (proton number) plus neutron number equals mass number: . The difference between the neutron number and the atomic number is known as the neutron excess: . ...

, the number of neutrons in a nuclide * N, in

Brillouin zone In mathematics and solid state physics, the first Brillouin zone (named after Léon Brillouin) is a uniquely defined primitive cell in reciprocal space Reciprocal lattice is a concept associated with solids with translational symmetry whic ...

, the center of a face of a body-centered cubic lattice * ''N'', the physical quantity "

rotation Rotation or rotational/rotary motion is the circular movement of an object around a central line, known as an ''axis of rotation''. A plane figure can rotate in either a clockwise or counterclockwise sense around a perpendicular axis intersect ...

" in the International System of Quantities * n, for

nano- Nano (symbol n) is a unit prefix meaning one billionth. Used primarily with the metric system, this prefix denotes a factor of 10−9 or . It is frequently encountered in science and electronics for prefixing units of time and length. The p ...

, prefix in the SI system of units denoting a factor of 10⁻⁹ * n, the optical

refractive index In optics, the refractive index (or refraction index) of an optical medium is the ratio of the apparent speed of light in the air or vacuum to the speed in the medium. The refractive index determines how much the path of light is bent, or refrac ...

of a material * n, the

principal quantum number In quantum mechanics, the principal quantum number (''n'') of an electron in an atom indicates which electron shell or energy level it is in. Its values are natural numbers (1, 2, 3, ...). Hydrogen and Helium, at their lowest energies, have just ...

, the first of a set of quantum numbers of an atomic orbital * n, an

electron density Electron density or electronic density is the measure of the probability of an electron being present at an infinitesimal element of space surrounding any given point. It is a scalar quantity depending upon three spatial variables and is typical ...

, the measure of the probability of an electron being present at a specific location * n, an

amount of substance In chemistry, the amount of substance (symbol ) in a given sample of matter is defined as a ratio () between the particle number, number of elementary entities () and the Avogadro constant (). The unit of amount of substance in the International ...

in chemical physics * n, the

coordination number In chemistry, crystallography, and materials science, the coordination number, also called ligancy, of a central atom in a molecule or crystal is the number of atoms, molecules or ions bonded to it. The ion/molecule/atom surrounding the central ion ...

of a substance * ''n-'', a lowercase prefix in chemistry denoting the straight-chain form of an

open-chain compound In chemistry, an open-chain compound (or open chain compound) or acyclic compound (Greek prefix ''α'' 'without' and ''κύκλος'' 'cycle') is a compound with a linear structure, rather than a Cyclic compound, cyclic one. An open-chain compound ...

in contrast to its branched isomer * ''N-'', an uppercase prefix in chemistry denoting that the substituent is bonded to the nitrogen, as in

amine In chemistry, amines (, ) are organic compounds that contain carbon-nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of elec ...

Transport

N (New York City Subway service) The N Broadway Express is a rapid transit service in the B Division of the New York City Subway. Its route emblem, or "bullet," is colored , since it uses the BMT Broadway Line in Manhattan. The N operates 24 hours daily between Ditmars Boule ...

, a service of the New York City Subway *

N Judah The N Judah is a hybrid light rail/streetcar line of the Muni Metro system in San Francisco, California. The line is named after Judah Street that it runs along for much of its length, named after railroad engineer Theodore Judah. It links down ...

, a Muni Metro line in San Francisco, California *

N (Los Angeles Railway) N was a streetcar line in Los Angeles, California. It was operated by the Los Angeles Railway from 1920 to 1950. The line ran from Spring and 2nd Streets to 8th Street and Western Avenue, by way of Spring Street, 9th Street, Vermont Avenue, an ...

, a line operated by the Los Angeles Railway from 1920 to 1950 *

Tokyo Metro Namboku Line The is a subway line owned and operated by Tokyo Metro in Tokyo, Japan. The line runs between Meguro in Shinagawa and Akabane-Iwabuchi in Kita. The Namboku Line was referred to as Line 7 during the planning stages, thus the seldom-used off ...

, a subway service operated by the Tokyo Metro, labeled Logo of Tokyo Metro Namboku Line

Nagahori Tsurumi-ryokuchi Line The is an underground rapid transit system in Osaka, Japan, operated by Osaka Metro. It was the first linear motor rapid transit line constructed in Japan (and the first outside North America, predated only by the Intermediate Capacity Transi ...

, a subway service operated by the Osaka Metro, labeled Osaka Metro Nagahori Tsurumi-ryokuchi line symbol

Transilien Line N Transilien Line N is a railway line of the Paris Transilien suburban rail network operated by the SNCF. The trains on this line travel between Gare Montparnasse in Paris and the west of Île-de-France region, with termini in Rambouillet, Dreux ...

, a line of the Paris transport network * JRW oka-N

, the official West Japan Railway Company service symbol for the

Akō Line is a railway line owned by West Japan Railway Company (JR West) between Aioi, Hyōgo to Okayama, Okayama in Japan. A loop line off the Sanyō Main Line, the Akō Line commences at Aioi, is situated south of the main line approximately parallel ...

Engineering

* N, in geotechnical engineering, the result of a

standard penetration test The standard penetration test (SPT) is an in-situ dynamic penetration test designed to provide information on the geotechnical engineering properties of soil. This test is the most frequently used subsurface exploration drilling test performe ...

* N, in electrical systems, the connection to neutral * N, an

ITU prefix The International Telecommunication Union (ITU) allocates call sign prefixes for radio and television stations of all types. They also form the basis for, but may not exactly match, aircraft registration identifiers. These prefixes are agreed upo ...

allocated to the United States for radio and television stations *

n (Poland) n was a Polish DTH platform. It was launched on October 12, 2006 and owned by ITI Neovision. On December 31, 2011 the company had reached 929,000 subscribers. On March 21, 2013, n merged with Cyfra+ to form nc+. History In May 2006, the ITI ...

, a digital TV platform * N battery or N cell, a standard size of dry cell battery *

N connector The N connector (also, type-N connector) is a threaded, weatherproof, medium-size RF connector used to join coaxial cables. It was one of the first connectors capable of carrying microwave-frequency signals, and was invented in the 1940s by P ...

, a threaded RF connector for joining coaxial cables

Entertainment

* ''N.'' (novella), a 2008 short story by Stephen King *

Near (Death Note) The manga series ''Death Note'' features an extensive cast of fictional characters designed by Takeshi Obata with their storylines created by Tsugumi Ohba."How to Think." ''Death Note: How to Read 13''. VIZ Media. 59. The story follows the characte ...

(alias ''N''), a character in the manga series ''Death Note'' * ''N'' (video game), a 2005 computer game * N (Pokémon), the leader and king of crime syndicate Team Plasma in the ''Pokémon'' franchise *

The N The N (standing for Noggin) was a prime time and late-night block programming, programming block on the Noggin (brand), Noggin television channel, aimed at preteens and teenagers. It was launched on April 1, 2002, by MTV Networks and Sesame Works ...

, a block on the Noggin TV channel *N, the production code for the 1965 ''Doctor Who'' serial ''

The Web Planet ''The Web Planet'' is the fifth serial of the second season in the British science fiction television series ''Doctor Who''. Written by Bill Strutton and directed by Richard Martin, the serial was broadcast on BBC1 in six weekly parts from ...

'' * '' "N" Is for Noose'', the fourteenth novel in Sue Grafton's "Alphabet mystery" series, published in 1998 * Serial Designation "N", one of the main characters from the web series '' Murder Drones'' (2021-2024)

Music

N (singer) Cha Hak-yeon (, born June 30, 1990), better known by his stage name N (), is a South Korean singer, actor, presenter, and radio host, signed to 51k. He debuted as a member of the South Korean boy band VIXX in May 2012, he began his acting care ...

, stage name of Cha Hak-yeon, leader of the South Korean boy band VIXX * N, an alias of Drew Mulholland, who recorded more often as Mount Vernon Arts Lab * ''N'' (album), a 2008 album by Norther * "N", a song by

BanYa Banya may refer to: Places Australia * Banya, Queensland, a locality in the Sunshine Coast Region, Queensland, Australia Bulgaria * Banya, Blagoevgrad Province, a thermal spa and mountain resort in southwest Bulgaria * Banya, Burgas P ...

for the "Pump It Up: The Perfect Collection" music video game * "n", a song by

iamamiwhoami iamamiwhoami ( ) is an electronic music and audiovisual project led by Swedish singer-songwriter Jonna Lee (singer), Jonna Lee in collaboration with producer Claes Björklund. Since 2009, the project has released a series of audiovisual works ...

Language

* , the

International Phonetic Alphabet The International Phonetic Alphabet (IPA) is an alphabetic system of phonetic notation based primarily on the Latin script. It was devised by the International Phonetic Association in the late 19th century as a standard written representation ...

symbol for a

voiced alveolar nasal The voiced alveolar nasal is a type of consonantal sound used in numerous spoken languages. The symbol in the International Phonetic Alphabet that represents dental, alveolar, and postalveolar nasals is , and the equivalent X-SAMPA symbol i ...

sound ** , , , , , , , , , , symbols representing other

nasal consonant In phonetics, a nasal, also called a nasal occlusive or nasal stop in contrast with an oral stop or nasalized consonant, is an occlusive consonant produced with a lowered velum, allowing air to escape freely through the nose. The vast majo ...

s in the International Phonetic Alphabet *

N (kana) ん, in hiragana or ン in katakana, is one of the Japanese kana, which each represent one Mora (linguistics), mora. ん is the only kana that does not end in a vowel sound (although in certain cases the vowel ending of kana, such as す, is unp ...

, a Japanese kana *

Noun In grammar, a noun is a word that represents a concrete or abstract thing, like living creatures, places, actions, qualities, states of existence, and ideas. A noun may serve as an Object (grammar), object or Subject (grammar), subject within a p ...

, a part of speech

Other uses

Hyundai N Hyundai N () is a sub-brand of high-performance cars, engines, and related technologies established in 2012 bHyundai Hyundai claims the "N" refers to two elements. First, the Hwaseong, Gyeonggi, Namyang district in South Korea, home of Hyundai ...

, high performance brand of Hyundai Motor Company * N,

North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating Direction (geometry), direction or geography. Etymology T ...

, one of the cardinal directions of the compass *

N postcode area The N (Northern) postcode area, also known as the London N postcode area, is the part of the London postal district, London post town covering part of North London, England. It is a group of 25 postcode districts which covers around 17,429 live ...

, the part of the London post town covering part of North London, England * ₦, the symbol for the

Nigerian naira The naira (sign: ₦; code: NGN; , , , ) is the currency of Nigeria. One naira is divided into 100 ''kobo''. The Central Bank of Nigeria (CBN) is the sole issuer of legal tender money throughout the Federal Republic of Nigeria. It controls t ...

currency * N, the code used to denote

vehicle registration plates of Norway The registration plates of cars in Norway are maintained by the Norwegian Ministry of Transport and Communications. As in most countries, cars are identified only by number plates read visually. Each plate is a legal document that both identifies ...

N-class ferry N-class ferries are a class of RORO ferries, of which one remaining example is owned by BC Ferries and has the distinction of being the smallest vessel in their fleet. The N class consists of four vessels: , sold to Mike Buttle Services in 2019 ...

, a class of small RORO ferry *

N scale N scale is a popular model railway scale. Depending upon the manufacturer (or country), the scale ranges from 1:148 to 1:160. Effectively the scale is 1:159, 9 mm to , which is the width of standard gauge railway. However the scale may ...

or N gauge, a popular model railway size * N, the identifier for the

knight (chess) The knight (♘, ♞) is a piece in the game of chess, represented by a horse's head and neck. It moves two squares vertically and one square horizontally, or two squares horizontally and one square vertically, jumping over other pieces. Each pla ...

in algebraic notation *

November November is the eleventh and penultimate month of the year in the Julian and Gregorian calendars. Its length is 30 days. November was the ninth month of the calendar of Romulus . November retained its name (from the Latin ''novem'' meaning " ...

, the military time zone code for UTC−01:00 *

Nachrichten-Abteilung The ''Nachrichten-Abteilung'', also known as N, was the naval intelligence department of the German Imperial Admiralty Staff or ''Admiralstab'' between 1901 and 1919. It focused its efforts on France, the United States and above all the United ...

, naval intelligence department of Imperial German