Of the following outer electronic configurations of atoms,which one achieves the highest oxidation state?

The correct order of decreasing second ionisation enthalpy of $Ti(22), V(23), Cr(24)$ and $Mn(25)$ is

How many of the following lanthanide elements exhibit $+4$ oxidation state?
$Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy$

Which of the following does not represent the correct order of the property indicated?

Identify the order in which the spin-only magnetic moment (in $BM$) increases for the following four ions:
$(I) Fe^{2+}$
$(II) Ti^{2+}$
$(III) Cu^{2+}$
$(IV) V^{2+}$

State whether the following statements are true or false:
$(i)$ Atomic size increases with an increase in the atomic number of elements.
$(ii)$ The electron gain enthalpy for noble gases is approximately zero.
$(iii)$ The first element of the actinoid series is $Th$ and the last element is $Lu$.
$(iv)$ The general electronic configuration of $d$-orbitals is always $(n-1)d^{1-10}ns^2$.