A mass spectrometer measures the relative abundances of isotopes of a Group 14 element. Two peaks appear at m/z = 28 (92.2%) and m/z = 29 (4.7%) and a small peak at m/z = 30 (3.1%).
What is the average atomic mass and identity of the element?
- A
27.98 amu, aluminum
- B
29.00 amu, phosphorus
- C
28.50 amu, silicon
- Dcheck_circle
28.11 amu, silicon
Explanation
Avg = (28)(0.922) + (29)(0.047) + (30)(0.031) = 25.82 + 1.363 + 0.93 = 28.11 amu. This matches silicon (28.09 amu).