Exercises: Photoelectron Spectroscopy

In a photoelectron spectrum, what do the horizontal axis and the vertical axis represent? Which electrons, those in the 1s subshell or those in the 2p subshell of the same atom, appear at higher binding energy, and why?

A photoelectron spectrum of an element shows three peaks with relative heights 2 : 2 : 1. Assuming the peaks are the 1s, 2s, and 2p subshells, write the electron configuration and identify the element.

Explain why a photoelectron spectrum of helium has one peak and a spectrum of lithium has two peaks.

The photoelectron spectrum of an element shows peaks at binding energies of 104 MJ/mol, 8.68 MJ/mol, 6.51 MJ/mol, and 0.58 MJ/mol with relative heights 2, 2, 6, and 2 in order from highest to lowest energy. Write the electron configuration of the element and identify it.

The 1s peak of neon appears near 84 MJ/mol, while the 1s peak of carbon appears near 29 MJ/mol. Explain this difference in terms of nuclear charge and Coulomb's law.

A photoelectron spectrum of an atom shows the following peaks: 1s at 309 MJ/mol (height 2), and four more peaks at lower energy with heights 2, 6, 2, and 6. Write the electron configuration that matches these heights through the 3p subshell, assuming no further peaks, and identify the element.

Compare the photoelectron spectra of sodium and potassium. (a) Give the expected number of peaks and their relative heights for each. (b) Explain which element has the lower binding energy for its outermost electrons, using atomic radius and shielding. (c) Explain why the 1s peak of potassium is at a much higher binding energy than the 1s peak of sodium.

A student claims that the photoelectron spectrum of magnesium has peaks with relative heights 2, 2, 6, 2, and that of aluminum has relative heights 2, 2, 6, 2, 1. (a) Verify or correct each claim. (b) Explain why the 3s peak of aluminum is at a slightly higher binding energy than the 3s peak of magnesium. (c) Predict how the position and height of the 3p peak of aluminum compare with its 3s peak, and justify your prediction.