Question

Spectroscopic studies show that S can have its outermost electron in its 3p Hartree orbital, and

Zeff(3p) = 5.48. Similarly, for O Zeff(2p) = 4.45. From this, estimate and compare the energies of the
outermost electrons in O and S. (Zeff values from Clementi and Raimondi / Chem Phys 38 2636
(1963).)
(0)

Answer 1

Using the given Zeff values for oxygen and sulfur and the principal quantum numbers, the energies of the outermost electrons in O and S are -119.4 eV and -104.1 eV, respectively, indicating that O's outermost electron is more tightly bound.

Step-by-step explanation:

To estimate and compare the energies of the outermost electrons in oxygen (O) and sulfur (S), one can use the effective nuclear charge (Zeff) and the principal quantum number (n).

The energy of an electron in an atom can be approximated using the formula

E = -13.6 * (Zeff)^2 / n^2 eV,

where E is energy, Zeff is the effective nuclear charge, and n is the principal quantum number.

Given that Zeff for O's 2p electron is 4.45 and for S's 3p electron is 5.48, we apply these values to the formula.

The principal quantum number for O's outermost electron is 2, and for S's is 3:

For O: E = -13.6 * (4.45)^2 / (2)^2 = -119.4 eV (approximately)

For S: E = -13.6 * (5.48)^2 / (3)^2 = -104.1 eV (approximately)

Comparing the two, the outermost electron in O has a more negative energy (is more tightly bound) than that in S, which is consistent with the concept of shielding and the effects of increased principal quantum numbers on electron energies.