The stability of a particular oxidation state of a metal in an aqueous solution can be determined by:

Identify the element having the highest enthalpy of atomization from the following.

The electrons which take part in order to exhibit variable oxidation states by transition metals are

Consider $n$ as the number of lone pairs of electrons present in the equatorial position of the most stable structure of $ClF_3$. The ions from the following with $n$ number of unpaired electrons are :
$A. V^{3+}$
$B. Ti^{3+}$
$C. Cu^{2+}$
$D. Ni^{2+}$
$E. Ti^{2+}$
Choose the correct answer from the options given below :

Electronic configuration of $Gd$ $(Z = 64)$ is

Which of the following elements in their respective oxidation states develops the highest spin-only magnetic moment?