1. A hypothetical pure element consists entirely of two isotopes. The natural percent abundance of the isotope with mass 25.5 u is 86.1%. The other isotope has mass 29.2 u. Calculate the atomic weight of the naturally occurring element.

Question

2. Suppose that a hypothetical element consists of a mixture of two isotopes. One isotope, having mass 44 amu, is present in 20.9% abundance, while the other isotope, having mass 46 amu, accounts for the other 79.1%. What should be the experimentally determined atomic weight for this hypothetical element?Answer in units of amu.

Answer 1

25.5(0.861) + 29.2(1-0.861) = ?

Answer 2

26

Answer 3

29.6
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