the mass of an isotope of an element measured in units formerly based on the mass of one hydrogen atom taken as a unit or on 1/16 (0.0625) the mass of one oxygen atom, but after 1961 based on 1/12 (0.0833) the mass of the carbon-12 atom.
Abbreviation: at. m.
The best evidence that these particles are of atomic mass is furnished by their deflection in electric and magnetic fields.
A Brief Account of Radio-activity Francis Preston Venable
the mass of an isotope of an element in atomic mass units
short for relative atomic mass See atomic weight
atomic mass n.
The mass of an atom, usually expressed in atomic mass units.
The mass of a given atom or molecule, expressed in atomic mass units. Compare atomic weight. See also mass number.
a plural suffix occurring in loanwords from Latin, forming nouns used especially in names of zoological groups: Vertebrata. a plural suffix occurring in loanwords from Greek: stomata. Associate Technical Aide. Contemporary Examples ata wants the government to state officially whether the reports are true or not. The Turks to ISIS: ‘Let’s Make a Deal’ Thomas […]
- Ata point
ata point unit, text (Or “Anglo-Saxon point”) One of the two most common variants of the point, equal to 0.3514598 mm, or 0.0138366 inch, or 1/72.272 inch. The ATA point is used on the island of the United Kingdom and on the American continent. [What point do they use in Ireland?] (2002-03-11)
ata-2 Advanced Technology Attachment Interface with Extensions
noun (NZ) another name for cat’s-eye (sense 2)