Neon has three naturally occurring isotopes. They include Ne-20, atomic mass of 19.992 amu and percent abundance of 90.48%; Ne-21, atomic mass of 20.994 amu and percent abundance of 0.27%; Ne-22 has a mass of 21.991 amu and percent abundance of 9.25%. Calculate the average atomic mass of neon?

Respuesta :

The three isotopes of neon are Ne-20 with atomic mass 19.992 amu and % abundance 90.48%, Ne-21 with atomic mass 20.994 amu and % abundance 0.27% and Ne-22 with atomic mass 21.991 amu and % abundance 9.25%.

The average atomic mass of Ne can be calculated as follows:

M=M(Ne-20)×%(Ne-20)+M(Ne-21)×%(Ne-21)+M(Ne-22)×%(Ne-22)

On putting the values,

M=(19.992 amu)(0.9048)+(20.994 amu)(0.0027)+(21.991 amu)(0.0925)=20.180 amu

Thus, average mass of neon is 20.180 amu