Identify all the correct statements for Lanthanide contraction. (A) The covalent properties of the Lanthanide metal hydroxides increases from La to Lu . (B) The chemical reactivity decreases from La to Lu . (C) La ( OH )₃ is more basic than Lu ( OH )₃ (D) Zr and Hf have about the same radius. (E) Separation of Lanthanides from one another is easy

Step-by-step solution

The change in ionic radii is Lanthanide series is very small, their chemical properties are small. Thus, the separation of Lanthanide is difficult due to consequence of Lanthanide contraction. The ionic radii of same positive charge of La to Lu decreases. So, the polarizing power towards hydroxyl group increases. Therefore the covalent character increases. Thus, La ( OH )₃ is more basic than Lu ( OH )₃ . Zr and Hf have the almost same radius as the electrons in the elements after Zr are added into the deep seated 4