Question

Neon consists of three isotopes: Neon-20 with a mass of 19.992 amu and an abundance of 90.48%, Neon-21with a mass of 20.994 amu and an abundance of 0.27%, and Neon-22 with a mass of 21.991 amu and an abundance of 9.25%. Determine the average atomic mass of Neon:

Answer 1

Average atomic mass= % abudnace of Neon-20 * its
atomic weight+ % abundance of Neon-21* its atomic
weight+ %abudance of neon-22* its atomic weight=
0.9048*19.992440 + (0.27/100)*20.993846+
0.0925*21.991385=20.18005