Calculating Relative Atomic Mass

Flashcards covering the calculation of relative atomic mass.

What is relative atomic mass?

A weighted average of all the mass numbers of the isotopes of an element.

What is the formula for calculating relative atomic mass?

Ar = (mass number 1 x abundance) + (mass number 2 x abundance) / total abundance

If the abundance is given in percentage, what should you do in the calculation?

Divide by 100.

If the percentage sign is not used, what should you do with the abundances?

Add up the abundances and use that for the total abundance.

What do we generally do with relative atomic masses after calculation?

Generally round them up.