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Talja [164]
3 years ago
8

Naturally occurring neon exists as three isotopes. 90.51% is ne-20 with a mass of 19.99 amu, 0.27% is ne-21 with a mass of 20.99

amu, and 9.22% is ne-22 with a mass of 21.99 amu. what is the atomic mass of neon?
Chemistry
1 answer:
gregori [183]3 years ago
3 0

The atomic mass of an element is the average relative mass of its atoms as compared with an atom of carbon-12 whose mass is taken as 12. In terms of percentages of different isotopes, the average atomic mass can be determined as follows: A_{average} = ∑(p_{i}X A_{i})/100. Where, p_{i} is the percentage abundance of isotope with atomic number A_{i}.

So, average atomic mass of neon = \frac{(90.51 X 19.99) + (0.27 X 20.99) + (9.22 X 21.99)}{100} = 20.177 amu.

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