Most common oxidation states of $Ce$ are

Which is the last element in the series of the actinoids? Write the electronic configuration of this element. Comment on the possible oxidation state of this element.

What is the electronic configuration of $Nd^{2+}$?

Describe the general chemical reactions of lanthanoids with the help of a diagram and state their uses.

Identify the correct decreasing order of atomic radii from the following.

Identify the correct statements from the following.
$(i)$ $Eu^{2+}$ and $Yb^{2+}$ are reducing agents.
$(ii)$ The electronic configuration of $Pr^{3+}$ is $[Xe] 4f^3$.
$(iii)$ Aqueous solution of $LaCl_3$ is colourless.