Explanation:
For all of the questions, do the following calculation
[tex] \frac{isotope \: \times abundance}{100} + \frac{isotope \: \times abundance}{100} ...[/tex]
As an example, I'll do question 1
[tex] \frac{204 \times 1.480}{100} + \frac{206 \times 23.6}{100} + \frac{207 \times 22.6}{100} + \frac{208 \times 52.3}{100} = 207.20[/tex]
