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Can anyone help ASAP!!

Can anyone help ASAP!!-example-1
User Jmetz
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1 Answer

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The formula to determine the average atomic mass is:

Average atomic mass =
mass of the isotope 1 * natural abundance of isotope 1 +
mass of the isotope 2 * natural abundance of isotope 2 + ........
+ mass of the isotope n * natural abundance of isotope n -(1)

The atomic mass of first isotope of magnesium = 24 u (given)

The natural abundance of first isotope = 78.70 % (given)

The atomic mass of second isotope of magnesium = 25 u (given)

The natural abundance of first isotope = 10.13 % (given)

The atomic mass of third isotope of magnesium = 26 u (given)

The natural abundance of first isotope = 11.17 % (given)

Substituting the values in formula (1):

atomic weight =
(24 * 0.7870) + (25 * 0.1013) + (26 * 0.1117)

atomic weight =
24.4625 u

Hence, the atomic weight of naturally occurring isotopic mixture is
24.4625 u.


User Justus Metzger
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