Question

1.) calculate the average atomic mass of sulfur if 95.00% of all sulfur atoms have a mass of 31.972 amu, 0.76% has a mass of 32.971 amu and 4.22% have a mass of 33.967 amu.

Explanation:

Step1: Convert percentages to decimals

For 95.00%: $95.00\% = \frac{95.00}{100} = 0.9500$
For 0.76%: $0.76\% = \frac{0.76}{100} = 0.0076$
For 4.22%: $4.22\% = \frac{4.22}{100} = 0.0422$

Step2: Multiply each mass by its decimal fraction

First isotope: $31.972 \times 0.9500 = 30.3734$
Second isotope: $32.971 \times 0.0076 = 0.2505796$
Third isotope: $33.967 \times 0.0422 = 1.4334074$

Step3: Sum the products

$30.3734 + 0.2505796 + 1.4334074 = 32.057387$

Answer:

The average atomic mass of sulfur is approximately 32.06 amu (rounded to two decimal places).