Question

11. If a hypothetical element consisted of three isotopes in the following relative abundance, what would the atomic

mass of the element be?
30.00% 30.00 amu
50.00% 32.00 amu
20.00% 35.00 amu

A. 33.00 amu
B. 32.25 amu
C. 32.00 amu
D. 31.50 amu
E. 31.00 amu

Answer 1

The average atomic mass of the hypothetical element with the given isotopic composition is 32.00 amu, calculated by multiplying each isotope's mass by its abundance and summing the products.

Step-by-step explanation:

To calculate the average atomic mass of a hypothetical element with three isotopes given their relative abundance and atomic mass units (amu), you need to use the concept of a weighted average. Each isotope's atomic mass is multiplied by its relative abundance (expressed as a fraction), and the resulting products are summed up to find the average atomic mass of the element.

Here's the calculation for the hypothetical element:

• 
  
• (0.30 × 30.00 amu) = 9.00 amu
• 
  
• (0.50 × 32.00 amu) = 16.00 amu
• 
  
• (0.20 × 35.00 amu) = 7.00 amu

Adding these products together: 9.00 amu + 16.00 amu + 7.00 amu = 32.00 amu Therefore, the average atomic mass of the element would be 32.00 amu, which corresponds to Option C.