Repeat this calculation using Slater's rules to estimate the screening constant, S, and calculate Zeff for these two ions. Express your answers using two decimal places. Enter your answers numerically separated by a comma. 50 A 6 A 0 21 ? S. Zeff C, Zeff K+ =

Cl^- = 5.75

K^+ = 7.75

Explanation:

Now let us calculate the effective nuclear charge four K^+ and Cl^- from Slater's rule.

Given that Cl^- and K^+ has electronic configuration of; [Ne] 3s2 3p6 (they are isoelectronic species)

We compute S as follows;

For n - 2 level, S= 1

For n - 1 level, S= 0.85

For ns,np level S= 0.35

Note: S= screening or shielding constant

1s2, S=2 ×1 = 2

2s2 2p6, S= 8×0.85 = 6.8

3s2 3p6, S= 7 × 0.35 = 2.45

The electron under study is not considered hence seven out of eight electrons in the shell are considered

Hence

S= 2 + 6.8 + 2.45 = 11.25

Since Cl^- has 17 electrons;

Zeff(Cl^-) = 17 - 11.25 = 5.75

For K^+

Zeff = 19 - 11.25 = 7.75

i think slash and

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.