masse atomique
- Domaine
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- chimie
- Date
Définition :
Masse pesante de 6,0247X10²3 (nombre d'Avogadro) atomes qui composent chaque élément. Elle a été déterminée en prenant la masse atomique de l'oxygène O=16; on a par suite H=1,0008, lithium =6,94, etc.
Terme :
- masse atomique n. f.
Traductions
-
anglais
Date :Définition
The mass of an atom of an element referred to one sixteenth of the mass of an atom of oxygen. The chemical unit ignores the presence of heavier isotopes of oxygen, and fixes the atomic weight of oxygen as 16.000. The physical unit allows for the presence of these isotopes and is therefore equal to 1.6603X10-24 g. The unit of atomic mass is the reciprocal of Avogadro's number (...), which is the number of atoms of an element in a gram-atom, which is in turn equal to the atomic weight of an element expressed in grammes.
Terme :
- atomic mass