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

Which of the following statements regarding Lanthanides is false?

Lanthanum $(La)$ is grouped with $f-$block elements because

Which elements exhibit nearly identical properties?

Determine the correct $(T)$ and incorrect $(F)$ statements from the following:
$(a)$ $Lu^{3+}$ and $Yb^{2+}$ are not paramagnetic.
$(b)$ Sheets are made from mischmetal.
$(c)$ Pipes are made from mischmetal.

An element with electronic configuration $[Rn]\, 7s^2\, 5f^3\, 6d^1$ will fall in