Read the following passage and answer the next five questions based on it:

In any transition series, as we move from left to right the \(d-\)orbitals are progressively filled and their properties vary accordingly

The above are the two series of f-block elements in which the chemical properties won't change much. The 5f-series elements are radioactive in nature and mostly are artificially synthesized in laboratories and thus much is not known about their chemical properties.

Identify the incorrect statement.

Second ionization enthalpy of Ag is greater than second ionization enthalpy of Pd

The correct answer is option 1. Second ionization enthalpy of Ag is greater than second ionization enthalpy of Pd

To identify the incorrect statement among the given options, let us analyze each one of the statements:

1. Second ionization enthalpy of Ag is greater than second ionization enthalpy of Pd: Incorrect Statement: The second ionization enthalpy of silver (Ag) is not greater than that of palladium (Pd). Generally, the ionization energies of transition metals tend to increase across a period due to increased nuclear charge and the removal of electrons from the same shell. Palladium, being to the right of silver in the periodic table, typically has a higher ionization energy.

2. Zr and Hf share almost identical nuclear properties: Correct Statement: Zirconium (Zr) and Hafnium (Hf) are in the same group (group 4) of the periodic table and exhibit very similar chemical properties due to the lanthanide contraction, which makes their atomic and ionic sizes almost identical.

3. Melting point of Mn is lower than that of Cr:n Correct Statement: The melting point of manganese (Mn) is indeed lower than that of chromium (Cr). Chromium has a higher melting point due to its stronger metallic bonding compared to manganese.

4. Interstitial compounds are non-stoichiometric and neither ionic nor covalent in nature: Correct Statement: Interstitial compounds are typically non-stoichiometric, and they involve small atoms (like hydrogen, carbon, or nitrogen) occupying the interstitial sites in a metal lattice. These compounds are characterized by metallic bonding rather than ionic or covalent bonding.

Based on the analysis, the incorrect statement is: 1. Second ionization enthalpy of Ag is greater than second ionization enthalpy of Pd