Four successive members of the first row transition elements are listed below with their atomic numbers. Which one of them is expected to have the highest third ionization enthalpy?

Which of the following ions is paramagnetic?

Which of the following pairs will have the same effective magnetic moment?

The electronic configuration of Gadolinium ($Gd$,$Z = 64$) is:

The correct decreasing order of spin only magnetic moment values $(BM)$ of $Cu^{+}$,$Cu^{2+}$,$Cr^{2+}$ and $Cr^{3+}$ ions is $:$

The correct statement$(s)$ about $Cr^{2+}$ and $Mn^{3+}$ is(are)
[Atomic numbers of $Cr = 24$ and $Mn = 25$]
$(A)$ $Cr^{2+}$ is a reducing agent
$(B)$ $Mn^{3+}$ is an oxidizing agent
$(C)$ Both $Cr^{2+}$ and $Mn^{3+}$ exhibit $d^4$ electronic configuration
$(D)$ When $Cr^{2+}$ is used as a reducing agent,the chromium ion attains $d^3$ electronic configuration