What is the relative atomic mass

What is atomic mass? Definition and explanation ...

The Atomic mass (atomic mass) is the mass or weight of a single atom. As a result, the respective atomic mass value contains the sum of the atomic components of proton, neutron and electron for a single atom.

Basically, there is a distinction between relative and absolute atomic mass. The absolute atomic mass is specified with any unit of measurement, e.g. kilograms, grams or the atomic mass unit (u). The weight of one u (1 u) is, for example, 1.66 * 10-27kg (= 0.00000000000000000000000000166kg). In contrast, the relative atomic mass a dimensionless number. Dimensionless means that there is no fixed unit of measure. The relative atomic mass instead refers to 1/12 of the mass of one 12C atom (carbon atom).

Nowadays it is possible to measure atomic masses that are as accurate as possible using mass spectrometers. The reason why the values ​​of the mass numbers are almost always so crooked is due to the fact that they are only average values ​​of the atomic masses of the various isotopes. Every chemical element occurs in a different isotope ratio on earth. The relations for the three isotopes of hydrogen look like this: 1H (99.9%), 2H (0.01%) and 3H (10 ^ -15%). The isotope ratio is included in the calculation of the relative atomic mass, because due to the different number of neutrons, the respective hydrogen isotopes also weigh different amounts.