What is the average atomic mass of an element composed of a series of isotopes, $X, Y, Z$ with respective masses, $18.473"amu", 19.962"amu", 21.469*"amu"$ , and respective abundances, $X=28.812%$ , $Y=28.757%$ ...?

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Answer 1 · 2018-02-07T21:40:29

We take the weighted average ..... and get $20.15*"amu"$

$"Average atomic mass"={18.473_"X"xx28.812%+19.962_"Y"xx 28.757% +21.469_"Z" xx(100-28.812-28.757)%}*"amu"$

$-=20.15*"amu"$ ...if I have done my 'rithmetic right...

How did I get the percentage abundance of $Z$ ?

And it is likely that we got the element neon. How did I know this?

What is the average atomic mass of an element composed of a series of isotopes, X, Y, ZX, Y, Z with respective masses, 18.473*"amu", 19.962*"amu", 21.469*"amu"18.473*"amu", 19.962*"amu", 21.469*"amu", and respective abundances, X=28.812%X=28.812%, Y=28.757%Y=28.757%...?