Which of the following transition metal is present in misch metal?

Which element from the following has a half-filled $4f$ orbital in its observed ground state?

In lanthanides,with an increase in atomic number,the atomic radius decreases,except for the element $\underline{X}$. What is $\underline{X}$?

Which of the following $f$-block elements exhibits the highest oxidation state?

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.

Which element from the following has the largest ionic size in the $+3$ state?