A mass spectrum of a gaseous sample shows three distinct peaks that correspond to…
CHEMISTRY · Multi-part · AP · Chemistry · Atomic Structure and Properties · Atomic Structure and Properties
Problem
A mass spectrum of a gaseous sample shows three distinct peaks that correspond to singly charged ions at m/z=24.0000, m/z=25.0050, and m/z=26.0010. The instrument reports the relative intensities of these peaks as 78.70%, 10.13%, and 11.17%, respectively.
A handbook lists the following average atomic masses (in amu) for four possible elements in the same region of the periodic table:
• Element W: 22.990
• Element X: 24.305
• Element Y: 26.982
• Element Z: 28.085
Assume that the spectrum arises from a pure sample of a single element whose ions all carry a +1 charge.
(a) Calculate the average atomic mass of the element represented in the spectrum, using the data provided.
(b) Determine which element (W, X, Y, or Z) is present in the sample. Support your answer with quantitative reasoning based on your result from part (a).