The three stable isotopes of neon `._10Ne^(20), ._10Ne^(21)` and `._10Ne^(22)` have respective abundances of `90.51%,0.27%` and `9.22%`. The atomic masses of the three isotopes are `19.99u, 20.99u` and `21.99u` respectively. Obtain the average atomic mass of neon.

Explanation

Atomic mass of `_(10)^(20)Ne,m_(1)=19.99" "u`
Abundance of `_(10)^(20)Ne,eta_(1)=90.51%`
Atomic mass of `_(10)^(21)Ne,m_(2)=20.99" "u`
Abundance of `_(10)^(21)Ne,eta_(2)=0.27%`
Atomic mass of `_(10)^(22)Ne,m_(3)=21.99" "u`
Abundance of `_(10)^(22)Ne,eta_(3)=9.22%`
The average atomic mass of neon is given as:
`m=(m_(1)eta_(1)+m_(2)eta_(2)+m_(3)eta_(3))/(eta_(1)+eta_(2)+eta_(3))`
`=(19.99xx90.51+20.99xx0.27+21.9.22)/(90.51+0.27+9.22)`
`=20.1771" "u`