Neon, has three different isotopes. 90.51% of neon atoms have a mass of 19.992 amu. 0.27% of neon atoms have a mass of 20.994 amu. 9.22% of neon atoms have a mass of 21.991 amu. What is the adverage atomic mass of neon. and how did you get that.
my answer: 20.992 amu. is it correct?
2007-09-11 13:20:12 · 3 answers · asked by nothinbutnet2009 4 in Science & Mathematics ➔ Chemistry
Hmmm, the book value is 20.179 amu.
See if your calculations match mine:
(0.9051 * 19.992) + (0.0027 * 20.994) + (0.0922 * 21.991) =
(18.0947592) + (0.0566838) + (2.0275702) = 20.1790132
So, rounding off, the answer I get matches the book value of 20.179 amu
I'll bet you dropped a decimal place in one of your percentages -- most likely the 0.27% conversion.
2007-09-11 13:49:48 · answer #1 · answered by Dave_Stark 7 · 0⤊ 1⤋
hey there, Oaky, you take all the isotopes (90.5, 0.2 and 9.3) add them up and divide by 3 to get the answer, which is 33.34. This number (33.34) is the average of all the isotopes, its also known as the atomic molar mass.
2016-05-17 10:15:41 · answer #2 · answered by ? 3 · 0⤊ 0⤋
AAM=(mass #1)(isotopic abundance #1)+(mass #2)(isotopic abundance #2)+(mass #3)(isotopic abundance #3)
AAM=(19.992)(.9051)+(20.994)(.0027)+(21.991)(.0922)
AAM=18.095+0.057+2.028
AAM=20.18amu
2007-09-11 13:44:52 · answer #3 · answered by Anonymous · 1⤊ 0⤋