0 the mass of a specific isotope of a particular chemical element, usually expressed in atomic mass units -- 原子質量（某化學元素同位素的質量，通常以原子質量單位的形式表達）
It is shorter than any other carbonhalogen bond, and shorter than single carbonnitrogen and carbonoxygen bonds, despite fluorine having a larger atomic mass.
These are significant in helium because of its low atomic mass of about four atomic mass units.
However, because oxygen-17 and oxygen-18 are also present in natural oxygen this led to two different tables of atomic mass.
However, atomic weight, ie, relative atomic mass, is a dimensionless quantity, and can not take the units of grams per mole.
Fullerenes are comparatively large and massive objects, having an atomic mass of about 720 u.
Melting points, boiling points, and bond lengths increase with the atomic mass of the halide.
It also showed that a radioactive element may have more than one atomic mass though the chemical properties are identical.
For example, a sample of chlorine contains 75.8% chlorine-35 and 24.2% chlorine-37, giving an average atomic mass of 35.5 atomic mass units.
