Atoms atomic mass unit

Atomic mass number—The total number of protons and neutrons in the nucleus of an atom. Atomic mass unit—One unit is equal to l/12th of the mass of a carbon-12 atom. 

The atomic mass is the average mass of an element in atomic mass units ("amu"). 

APW (augmented plane wave) a band structure computation method atomic mass unit (amu) atomic unit of mass... 

The peak at m/z 77 m the mass spectrum of chlorobenzene m Figure 13 41 is attributed to this fragmentation Because there is no peak of significant intensity two atomic mass units higher we know that the cation responsible for the peak at m/z 77 cannot contain chlorine... 

Circumference divided by IT Dalton (atomic mass unit) Da... 

A typical resin has an initial molecular weight of 150 to perhaps 1500. For systems of unsubstituted phenols, the final cross-link density is 150—300 atomic mass units (amu) per cross-link. In other words, 25—75% of the ring-joining reactions occur during the cure phase. 

In Laser Ionization Mass Spectrometry (LIMS, also LAMMA, LAMMS, and LIMA), a vacuum-compatible solid sample is irradiated with short pulses ("10 ns) of ultraviolet laser light. The laser pulse vaporizes a microvolume of material, and a fraction of the vaporized species are ionized and accelerated into a time-of-flight mass spectrometer which measures the signal intensity of the mass-separated ions. The instrument acquires a complete mass spectrum, typically covering the range 0— 250 atomic mass units (amu), with each laser pulse. A survey analysis of the material is performed in this way. The relative intensities of the signals can be converted to concentrations with the use of appropriate standards, and quantitative or semi-quantitative analyses are possible with the use of such standards. 

Electron Mass = 0.910953 x 10 Kilograms 1 Atomic Mass Unit = 1822.8880 Electron Mass 1 Proton Mass = 1836.1527 Electron Mass [5]... 

To set up a scale of atomic masses, it is necessary to establish a standard value for one particular species. The modem atomic mass scale is based on the most common isotope of carbon, 1 C. This isotope is assigned a mass of exactly 12 atomic mass units (amu) ... 

This can result in a radioactive product from the A(n, t)A reaction where A is the stable element, n is a thermal neutron, A is the radioactive product of one atomic mass unit greater than A, and y is the prompt gamma ray resulting from the reaction. A is usually a beta and/or gamma emitter of reasonably long half-life. Where access to a nuclear reactor has been convenient, thermal neutron activation analysis has proven to be an extremely valuable nondestructive analytical tool and in many cases, the only method for performing specific analyses at high sensitivities... 

Because the masses of nuclides are so small, they are normally reported as a multiple of the atomic mass constant, ma (formerly atomic mass unit, amu). The atomic mass constant is defined as exactly V12 the mass of one atom of carbon-12 ... 

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