Amount of angular momentum associated with a subatomic particle or nucleus. It is measured in multiples of planck (h-bar), equal to Planck's constant divided by 2π. Electrons, neutrons, and protons have a spin of 12, for example, while pions and helium nuclei have zero spin. The spin of a complex nucleus is the vector sum of the orbital angular momentum and intrinsic spins of the constituent nucleons. For nuclei of even mass number, the multiple is an integral; for those of odd mass number, it is a half-integer. Seealso Bose-Einstein statistics, Fermi-Dirac statistics.

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Property characteristic of families of related subatomic particles differing mainly in the values of their electric charge. The families are known as isospin multiplets. The components of atomic nuclei, the neutron and the proton, form an isospin doublet since they differ only in electric charge and subsidiary properties. They are considered different versions of the same object, called a nucleon. The isospin of a nucleon has a value of 12.

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Technique of spectroscopic analysis (see spectroscopy) used to identify paramagnetic substances (see paramagnetism) and investigate the nature of the bonding within molecules by identifying unpaired electrons and their interaction with their immediate surroundings. Unpaired electrons, because of their spin, behave like tiny magnets and can be lined up in an applied magnetic field; energy applied by alternating microwave radiation is absorbed when its frequency coincides with that of precession of the electron magnets in the sample. The graph or spectrum of radiation absorbed as the field changes gives information valuable in chemistry, biology, and medicine.

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Spin may refer to:

• Rotation or spin, a movement of an object in a circular motion
• Spin (physics) or particle spin, a fundamental property of elementary particles
• Spin (flight), a special and often intense case of a stall
• Spin (public relations), a heavily biased portrayal of an event or situation
• Spin (breakdance move)
• Spinning (textiles), the process of creating yarn from various raw fiber materials

In media:

• Spin (film), a 1995 documentary film of politicians' behind-the-scenes conversations
• Spin (novel), a novel by Robert Charles Wilson
• Spin (magazine), a pop music magazine
• "Spin" (House episode)

In music:

• Spin (radio), a single play of a song
• Spin (band), a band from the Maltese Islands
• Spin (album), the first solo album by Darren Hayes
• "Spin" (Lifehouse song), a song by Lifehouse from Stanley Climbfall
• "Spin", a song by Taking Back Sunday from Louder Now
• "Spinnin'", a song by Soul Asylum from And the Horse They Rode in On
• "Spinning", a song by Christopher Cross from Christopher Cross
• Spin (Eric Roche album), an album by Eric Roche

In sports:

• Spin bowling, a type of bowling technique in cricket
• Spinning, a form of high-intensity exercise using a stationary exercise bicycle
• Poi spinning, a form of juggling
• Figure-skating spin, a skating move
• Wheelspin, spinning the wheels of a vehicle in place

In computing:

• SPIN (software) or Secure Peered Internet
• Spin (programming language), a high-level programming language
• SPIN (operating system), an OS based on Mach
• SPIN (software process), a Software Process Improvement Network
• SPIN model checker, a software tool
• Busy spin, a technique in which a process continually checks whether a condition is true

In other uses:

• Spin group, a particular double cover of the special orthogonal group SO(n)
• Metal spinning, the process of forming metal over a mandrel while spinning around a lathe
• Sufi spinning, a twirling meditation
• Fokker Spin, an airplane built by Anthony Fokker

See also

• Spinning Around, a song by Kylie Minogue