Match List I with List II.

Choose the correct answer from the options given below: 

A-I, B-III, C-II, D-IV

The correct answer is Option (2) → A-I, B-III, C-II, D-IV.

Let us delve deeper into each element from List I and its corresponding match in List II.

A. Ni (Nickel)

Nickel is a transition metal, specifically found in the 3d series of the periodic table.

Electronic Configuration: The electronic configuration of Ni is \([Ar] 3d^8 4s^2\).

Properties:

Nickel is known for its ability to form various oxidation states, with +2 being the most common.

It is a good conductor of electricity and is used extensively in alloys and catalysts.

Match:  The correct match is I. 3d Series since Nickel belongs to this series.

B. Cu (Copper)

Copper is also a transition metal and has a unique electron configuration.

Electronic Configuration: The configuration is \([Ar] 3d^{10} 4s^1\). In its +1 oxidation state, it achieves a filled d-orbital configuration \((d^{10})\).

Properties:

Copper is well-known for its electrical conductivity and resistance to corrosion.

It is widely used in electrical wiring and plumbing.

Match: The correct match is III. \(d^{10}\), as copper in its stable oxidation state features a complete d-orbital.

C. Gd (Gadolinium)

Gadolinium is a member of the lanthanide series, which includes the elements from lanthanum (La) to lutetium (Lu).

Electronic Configuration: The configuration is \([Xe] 4f^7 6s^2\).

Lanthanoid Contraction:  This term describes the gradual decrease in size of lanthanide ions with increasing atomic number due to poor shielding of the nuclear charge by the f-electrons.

Gadolinium, being in the middle of the series, exhibits noticeable contraction effects in ionic radii.

Match: The correct match is II. Lanthanoid contraction, as this phenomenon is prominent in gadolinium and its neighbors.

D. Cs (Cesium)

Cesium is an alkali metal located in Group 1 of the periodic table.

Electronic Configuration: The configuration is \([Xe] 6s^1\).

Properties:

Alkali metals are characterized by their high reactivity, particularly with water, forming hydroxides and releasing hydrogen gas.

Cesium is one of the most reactive and has the lowest ionization energy among the alkali metals.

Match: The correct match is IV. Alkali metal, as cesium is a prime example of this group.

Conclusion

Each element is matched to its appropriate description based on its properties and behavior in the periodic table. This analysis emphasizes the unique characteristics and classifications of these elements, leading to the conclusion that the correct matches are: A-I, B-III, C-II, D-IVmmmmm