The transition element ( $\approx 5 \%$ ) present with lanthanoid metal in misch metal is

Which of the following is responsible for the lanthanoid contraction?

The lanthanide ion having four unpaired electrons is
(Given : Atomic number of $Ce = 58, Nd = 60, Tb = 65$ and $Ho = 67$)

Which is the general formula for the electronic configuration of the actinide series?

Which of the following lanthanoid elements exhibits common oxidation states of $+2$ and $+3$?

What are inner transition elements? Decide which of the following atomic numbers are the atomic numbers of the inner transition elements: $29, 59, 74, 95, 102, 104$.