Question

Calculate the effective nuclear charge of of 3p electron of iron atom

Answer 1

Answer:

We need to find the effective nuclear charge for 4s electron in Fe atom with atomic number 26.

For that, we will use Slater's rules to calculate the effective nuclear charge. Writing the electronic configuration in Slater's notation.

        (1s)²  (2s2p)⁸  (3s3p)⁸ (3d)⁶  (4s)²

According to Slater's rules:                                                                       shielding by n=4 electron = 0.35 unit                                                                       by n-1=3 electrons = 0.85 unit                                                                       by n-2 and further electrons (for n=1,2) = 1.0 unit

Now, calculating the shielding constant for 4s electron:

        σ = 1×0.35 + 6×0.85 + 8×0.85 + 8×1.0 + 2×1.0

        σ = 22.25

So, the effective nuclear charge = Atomic number - Shielding constant

        Z* = Z - σ = 26 -  22.25 = 3.75

       So, correct answer is option 1) 3.75

Explanation:

Answer 2

Effective nuclear charge is the amount of positive charge on the electron by polyelectronic atom

Explanation:

Effective Nuclear Charge is the net positive charge of valence electrons.

It is represented by Zeff=Z-S

Electronic configuration of Iron=26 -1s²,2s².2p⁶.3s²,3p⁶,3d⁶,4s²

According to slaters rule-

3s²,3p⁶ → (n-2) (for n=1,2) →no of electrons is  2;                               contribution to s value 1;  S=2

2s².2p⁶→ (n-1 )=3 electrons→contribution to s value 0.85;

1s²→ n → no of electrons is  2;contribution to s value 0.35; s= 0.70

s=1×0.35+6×0.85+8×0.85+8×1.0+2×1

Total s=22.25

Zeff=Z-S

Zeff=26-22.25

Zeff= 3.75

The effective nuclear charge of 3p electron of Iron atom is 3.75