Question

which of the following correctly identifies which has the higher first - ionization energy, cl or ar, and supplies the best justification?
(a) cl, because of its higher electronegativity
(b) cl, because of its higher electron affinity
(c) ar, because of its completely filled valence shell
(d) ar, because of its higher effective nuclear charge
the complete photoelectron spectrum of a pure element is shown in the diagram above.
**8. according to the complete photoelectron spectrum, which of the following is the identity of the element?
(a) be
(b) c
(c) o
(d) ne
**9. if peaks 1 and 2 represent s sublevels, which of the following sublevels is represented by peak 3?
(a) s
(b) p
(c) d
(d) f
a certain element has two naturally occurring isotopes, as shown in the table.

Explanation:

8.

• For photoelectron spectra, the number of peaks corresponds to the number of electron - containing sub - shells.
• The heights of the peaks (relative number of electrons) give the number of electrons in each sub - shell.
• Peak 1: \(1s^{2}\) (84 binding energy, 2 electrons), Peak 2: \(2s^{2}\) (6 binding energy, 2 electrons), Peak 3: \(2p^{6}\) (2 binding energy, 6 electrons).
• The electron configuration is \(1s^{2}2s^{2}2p^{6}\), which is the electron configuration of neon (\(Ne\)).

• We know that \(s\) sub - shells can hold a maximum of 2 electrons, \(p\) sub - shells can hold a maximum of 6 electrons, \(d\) sub - shells can hold a maximum of 10 electrons, and \(f\) sub - shells can hold a maximum of 14 electrons.
• Peaks 1 and 2 are \(s\) sub - shells (2 electrons each). Peak 3 has 6 electrons.
• Since the \(p\) sub - shell has a capacity of 6 electrons, peak 3 represents the \(p\) sub - shell.

Answer:

D. Ne

9.