Question

indium(atomic wt.= 114.82 u ) has two naturally occuring isotopes, the predominant one from has isotopic wt. 114.9041 and abundance of 95.72%. which of the following isotopic wt. is the most likely for the other isotope?

Answer 1

no answer choices.
abundance first isotope = 95.72%
abundance other isotope is 100-95.72 = 4.28%
Let x = mass other isotope

(114.9041*0.9572) + (x*0.0428) = 114.82
Solve for x

Answer 2

112.94

Answer 3

Let atomic weight of other isotope is M

114.82= 114.9041×95.72 + 4.28×M ÷ 100

M = 112.94

Answer 4

112.94