The lanthanide contraction is responsible for the fact that

Which lanthanoid element has the electronic configuration $[Xe]4f^7 5d^1 6s^2$?

The element having electronic configuration $ns^2(n-1)d^{1-10}(n-2)f^{1-14}$ belongs to:

Choose the correct option regarding the following.
Assertion: Actinides exhibit a larger number of oxidation states than lanthanides.
Reason: There is a large energy gap between $5f$,$6d$ and $7s$ sub-shells.

The chemistry of the actinoid elements is not so smooth as that of the lanthanoids. Justify this statement by giving some examples from the oxidation states of these elements.

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