Question

1 point

an element has four isotopes. Isotope 1 has a percent abundance of 4,345%, Isotope 2 has a percent abundance of 9.501%, and Isotope 3 has a percent abunda
of 2.366%. What is the percent abundance of the fourth isotope (Isotope 4)? Make sure your answer is rounded to the correct number of significant figures (if
applicable).

Answer 1

The percent abundances of all isotopes of an element should add up to 100%. Given the percent abundances of three isotopes (Isotope 1, Isotope 2, and Isotope 3), you can find the percent abundance of the fourth isotope (Isotope 4) by subtracting the sum of the three known abundances from 100%.

Percent abundance of Isotope 4 = 100% - (Percent abundance of Isotope 1 + Percent abundance of Isotope 2 + Percent abundance of Isotope 3)

Percent abundance of Isotope 4 = 100% - (4.345% + 9.501% + 2.366%)

Now, calculate this:

Percent abundance of Isotope 4 ≈ 83.788%

Rounded to the correct number of significant figures, the percent abundance of Isotope 4 is approximately 83.8%.