A student is provided with a qualitative PES trace for an unknown element Q
CHEMISTRY · Multi-part · AP · Chemistry · Atomic Structure and Properties · Atomic Structure and Properties
Problem
A student is provided with a qualitative PES trace for an unknown element Q. The x-axis is labeled only with the phrase “increasing binding energy →,” while the y-axis shows relative intensity. No numerical scale is provided. The spectrum shows five discrete peaks, listed below in order of decreasing binding energy.
Peak order (highest to lowest binding energy)
Relative peak area
1
2
2
2
3
6
4
2
5
1
Respond to the tasks below.
(a) Arrange the following subshells—3s, 3p, 4s, 2p, 2s—in order of increasing binding energy and justify your ordering with reference to both nuclear attraction and electron shielding.
(b) Assign each of the five observed peaks to a specific subshell and state the number of electrons in that subshell.
(c) Write the complete ground-state electron configuration of element Q and determine its atomic number.
(d) Predict whether the first ionization energy of element Q is greater than, less than, or approximately equal to that of the element immediately to its right on the periodic table. Justify your prediction using both the PES information and periodic trends.