Editing Relative atomic mass (section)

== Other measures of the mass of atoms ==

'''[[Atomic mass]]''' (''m''<sub>a</sub>) is the mass of a single atom. It defines the mass of a specific isotope, which is an input value for the determination of the relative atomic mass. An example for three [[silicon]] isotopes is given below. A convenient unit of mass for atomic mass is the [[Dalton (unit)|dalton]] (Da), which is also called the unified atomic mass unit (u).

The '''relative ''isotopic'' mass''' is the ''ratio of'' the mass of a single atom to the [[atomic mass constant]] ({{nowrap|1=''m''<sub>u</sub> = 1&nbsp;Da}}). This ratio is dimensionless.