Question

What value do you estimate for Zeff experienced by the outermost electron in both Si and Cl, assuming that core electrons contribute 1.00 and valence electrons contribute 0.00 to the screening constant? What values do you estimate for Zeff using Slater's rules?

a) Zeff in Si = 2.00 and Zeff in Cl = 8.00
b) Zeff in Si = 3.00 and Zeff in Cl = 7.00
c) Zeff in Si = 4.00 and Zeff in Cl = 6.00
d) Zeff in Si = 5.00 and Zeff in Cl = 5.00

Answer 1

The Zeff experienced by the outermost electron in Si would be 12 and in Cl it would be 10. When applying Slater's rules, the Zeff in Si is estimated to be approximately 12, and in Cl it is approximately 9. Therefore, the correct answer is d) Zeff in Si = 5.00 and Zeff in Cl = 5.00.

Step-by-step explanation:

When determining the effective nuclear charge (Zeff), core electrons are considered to have a constant screening constant of 1.00, while valence electrons have a screening constant of 0.00. In the case of Si, which has 14 electrons, two of which are valence electrons, the Zeff experienced by the outermost electron would be 14 - 2 = 12.

On the other hand, Cl has 17 electrons with 7 valence electrons. Therefore, the Zeff experienced by the outermost electron in Cl would be 17 - 7 = 10.

According to Slater's rules, the Zeff can also be estimated using a set of empirical values. Since Si has 14 electrons, we can consider the inner core electrons to contribute a screening constant of 0.35 each, while the valence electrons contribute 0.85. Therefore, the Zeff in Si would be 14 - (2 x 0.35) - (2 x 0.85) = 14 - 0.7 - 1.7 = 11.6, which is approximately 12.

For Cl, with 17 electrons and 7 valence electrons, the inner core electrons would contribute 0.35 each, while the valence electrons contribute 0.85 each. Therefore, the Zeff in Cl would be 17 - (7 x 0.35) - (7 x 0.85) = 17 - 2.45 - 5.95 = 8.6, which is approximately 9. Therefore, the correct option would be d) Zeff in Si = 5.00 and Zeff in Cl = 5.00.