What is the average atomic mass of lithium?

1 Answer
Jan 30, 2016

Answer:

The major isotopes of lithium are (i) #""^7Li#, and (ii) #""^6Li#. The weighted average of these isotopes is #6.941# #g*mol^-1#.

Explanation:

You will have to look up the isotopic distribution of lithium nuclei. ALL lithium nuclei have 3 positively charged nuclear particles, protons, i.e. #Z# #=# #3#. These 3 particles give rise to the element's identity. If you take the weighted average of ALL lithium nuclei, we get an average mass of #6.941# #g*mol^-1#.