A simplified photoelectron spectrum (PES) for a gaseous sample of element X is…
CHEMISTRY · Multi-part · AP · Chemistry · Atomic Structure and Properties · Atomic Structure and Properties
Problem
A simplified photoelectron spectrum (PES) for a gaseous sample of element X is described below.
• Four distinct peaks are observed at binding energies of approximately 1250 eV, 400 eV, 95 eV, and 50 eV.
• The relative peak areas (height × width) are in the integer ratio 2 : 2 : 6 : 2, listed in the same order as the binding energies.
• The most energetic peak is the narrowest; the least energetic peak is the broadest.
Answer the following questions about the spectrum.
(a) Identify which peak in the spectrum corresponds to the 2p electrons of element X. Justify your answer using both peak position and electron count.
(b) Explain why the peak at 1250 eV has both the greatest binding energy and the smallest relative area.
(c) Describe two specific features of this spectrum that provide experimental evidence for the modern shell model of the atom.