General Introduction of Lanthanoids

Which of the following oxidation states is common for all lanthanoid?

Lanthanide contraction is caused due to:

The element with atomic number $61$ belongs to which group?

Which of the following statement is not correct :-

In $\mathrm{d}$-Block when atomic size of one series are compared with those of corresponding element in other series :-
(I) Increase from the first $\left(3\mathrm{d}\right)$ to second $\left(4\mathrm{d}\right)$ series
(II) Increase from the second $\left(4\mathrm{d}\right)$ to third $\left(5\mathrm{d}\right)$ series
(III) Virtually the same as first $\left(3\mathrm{d}\right)$ and in second $\left(4\mathrm{d}\right)$ series
(IV) Virtually the same as second $\left(4\mathrm{d}\right)$ and in third $\left(5\mathrm{d}\right)$ series

The most common oxidation state of lanthanoids is

The general oxidation state of Lanthanoid series is

Which of the following oxidation state is common for all lanthanoids?

The pair that has similar atomic radii is:

Among the following statements, which statement is not correct for lanthanides?

In periodic table, the $15$ elements placed in the $\mathrm{III}$ group and $\mathrm{VI}$ period are called as:

Choose the stable oxidation states of cerium ($\mathrm{Ce}$).

Lanthanoid contraction is due to:

The electronic configurations of bivalent europium and trivalent cerium are respectively
(atomic number: $\mathrm{X}\mathrm{e}=54,\mathrm{C}\mathrm{e}=58,\mathrm{E}\mathrm{u}=63$ )

Arrange the following ions in increasing order of their ionic radii, $\mathrm{C}{\mathrm{e}}^{+3},\mathrm{L}{\mathrm{a}}^{+3},\mathrm{P}{\mathrm{m}}^{+3}$ and $\mathrm{Y}{\mathrm{b}}^{+3.}$

Which of the following pairs has the same size?

The atomic number of cerium $\left(Ce\right)$ is 58. The correct electronic configuration of $C{e}^{3+}$ ion is

The correct increasing order of ionic radii of the following $C{e}^{3+}, L{a}^{3+}, P{m}^{3+} \mathrm{a}\mathrm{n}\mathrm{d} Y{b}^{3+}$ is

Choose the incorrect statement among the following.

Which of the following is a good reducing agent?