Why is there an atomic mass unit?

1 Answer
May 28, 2018

Why? Because atoms have definite and measurable masses....

Explanation:

We could report atomic masses with units of grams or kilograms. And thus an ""^1H1H atom has a mass of 1.67xx10^-24 *kg1.67×1024kg or 1.67xx10^-21 *g1.67×1021g. This is a bit inutile given that the we have to go thru the rigmarole of exponents, and even here they are a pain to write down and format....

Historically, while the mass of an hydrogen atom could not be experimentally measured … its mass could be inferred by reference to the mass of other atoms and molecules... and historically 1*"amu"1amu was 1/12*"th"112th the mass of the ""^12C12C "isotope.."isotope..