Statement I: Zr and Hf exhibit similarity in properties

Statement II: Zr and Hf lie in same group of the periodic

Statement I and Statement II are true and statement II is not correct explanation of statement I

The answer is 2. Statement I and Statement II are true but statement II is not correct explanation of statement I.

Statement I is true because Zr and Hf are both transition metals in the same group (IVB) of the periodic table. This means that they have similar electronic configurations and similar chemical properties.

Statement II is also true, but it is not the correct explanation for statement I. The fact that Zr and Hf lie in the same group of the periodic table is a necessary condition for them to exhibit similar properties, but it is not a sufficient condition. There are other elements that lie in the same group of the periodic table, but they do not exhibit similar properties to Zr and Hf.

The correct explanation for why Zr and Hf exhibit similar properties is that they have nearly the same atomic radii. This is because of the lanthanide contraction, which causes the atomic radii of the lanthanide elements to be smaller than expected. As a result, the atomic radii of Zr and Hf are very similar, which leads to similar chemical properties.

Therefore, both statements are true, but statement II is not the correct explanation for statement I. The correct explanation is that Zr and Hf have nearly the same atomic radii.