The pair of lanthanides in which both elements have high third - ionization energy is :

Given below are two statement: one is labelled as Assertion $$\mathbf{A}$$ and the other is labelled as Reason $$\mathbf{R}$$

Assertion A: $$5 \mathrm{f}$$ electrons can participate in bonding to a far greater extent than $$4 \mathrm{f}$$ electrons

Reason R: $$5 \mathrm{f}$$ orbitals are not as buried as $$4 \mathrm{f}$$ orbitals

In the light of the above statements, choose the correct answer from the options given below

Prolonged heating is avoided during the preparation of ferrous ammonium sulphate to :

Which of the following statements are correct?

(A) The M$$^{3+}$$/M$$^{2+}$$ reduction potential for iron is greater than manganese.

(B) The higher oxidation states of first row d-block elements get stabilized by oxide ion.

(C) Aqueous solution of Cr$$^{2+}$$ can liberate hydrogen from dilute acid.

(D) Magnetic moment of V$$^{2+}$$ is observed between 4.4 - 5.2 BM.

Choose the correct answer from the options given below :