Question

Answer the following question. Show your work to receive credit. A hypothetical element has an atomic weight of 48.68 amu. It consists of three isotopes having masses of 47.00 amu, 48.00 amu, and 49.00 amu. The lightest-weight isotope has a natural abundance of 10.0%. What is the percent abundance of the heaviest isotope?

Answer 1

percent abundance of the heaviest isotope is 78 %

Step-by-step explanation:

given data

atomic weight = 48.68 amu

mass 1 = 47 amu

mass 2 = 48 amu

mass 3 = 49 amu

natural abundance = 10 %

to find out

percent abundance of the heaviest isotope

solution

we consider here percent abundance of the heaviest isotope is x

so here lightest isotope = 47 amu of 10 % ..........1

and heaviest isotope = 49 amu of x ................2

and middle isotope = 48 amu of 100 - 10 - x ........3

so

average mass = add equation 1 + 2 + 3

average mass = 10% ( 47) + x% ( 49) + (90 - x) % (48)

48.68 = 4.7 + 0.49 x + 43.2 - 0.48 x

x = 0.78

so percent abundance of the heaviest isotope is 78 %