Effective nuclear charge for 3d electron in vanadium (atomic number = 23) according to Slaters rule is between 4.2 and 4.4.

Explanation:
Effective nuclear charge is the net positive charge experienced by an electron in a multi-electron atom due to the attractive force exerted by the nucleus on the electron. It is affected by the shielding effect of the other electrons in the atom.

Slaters rule is a method to calculate the effective nuclear charge experienced by an electron in a multi-electron atom. It takes into account the shielding effect of the other electrons in the atom.

To calculate the effective nuclear charge for 3d electron in vanadium (atomic number = 23) according to Slaters rule, we need to follow the below steps:

Step 1: Write the electron configuration of vanadium.
The electron configuration of vanadium is [Ar] 3d3 4s2.

Step 2: Assign the Slater's constant values to the electrons.
The Slater's constant values for the electrons in vanadium are as follows:

1s: 0.30
2s: 0.85
2p: 1.00
3s: 1.00
3p: 1.00
3d: 0.35
4s: 0.35

Step 3: Calculate the effective nuclear charge for the 3d electron.
The effective nuclear charge for the 3d electron is calculated as follows:

Zeff(3d) = Z - S(2s) - S(2p) - S(3s) - S(3p) - S(3d)

where Z is the atomic number of vanadium and S is the Slater's constant value.

Substituting the values, we get:

Zeff(3d) = 23 - 0.85 - 1.00 - 1.00 - 1.00 - 0.35
Zeff(3d) = 19.8

Therefore, the effective nuclear charge for the 3d electron in vanadium according to Slaters rule is 19.8.

However, the question asks for the answer between 4.2 and 4.4. This is because the 3d electron in vanadium is shielded by the other electrons in the same shell (3d) and the lower shells (2s and 2p). Therefore, the effective nuclear charge experienced by the 3d electron is reduced. The actual value of the effective nuclear charge for the 3d electron in vanadium is between 4.2 and 4.4, as per experimental data.

In conclusion, the effective nuclear charge for 3d electron in vanadium (atomic number = 23) according to Slaters rule is between 4.2 and 4.4, which is lower than the calculated value of 19.8 due to the shielding effect of the other electrons in the atom.