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title: "A student hypothesizes that inner-shell (core) electrons shield outer-shell (valence) electrons from the full attractive force of the nucleus. Which of the following observations from photoelectron spectroscopy (PES) data provides the best evidence to support this hypothesis?"
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url: "https://nerd-notes.com/ubq/119189/"
date_modified: "2026-08-19T12:39:14+00:00"
---

# A student hypothesizes that inner-shell (core) electrons shield outer-shell (valence) electrons from the full attractive force of the nucleus. Which of the following observations from photoelectron spectroscopy (PES) data provides the best evidence to support this hypothesis?

A student hypothesizes that inner-shell (core) electrons shield outer-shell (valence) electrons from the full attractive force of the nucleus. Which of the following observations from photoelectron spectroscopy (PES) data provides the best evidence to support this hypothesis?

- **A.** The observation that the binding energy of \(1s\) electrons increases continuously across Period 2 elements from lithium (\(Z = 3\)) to neon (\(Z = 10\)).
- **B.** The observation that the relative peak height for the \(2p\) subshell in neon is three times greater than the relative peak height for its \(2s\) subshell.
- **C.** The observation that the binding energy of the valence electron drops sharply from neon (\(Z = 10\)) to sodium (\(Z = 11\)), despite the increase in nuclear charge.
- **D.** The observation that the binding energy of \(2s\) electrons is slightly higher than the binding energy of \(2p\) electrons within the same shell of a neon atom.

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