Which of the metal ion will have the highest number of unpaired electrons?

The most stable oxidation state of $Cr$ in aqueous medium is

In a transition series,as the atomic number increases,paramagnetism

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Generally, $3d$ transition metals have high melting points.
Reason $R$: Involvement of $3d$-electrons in addition to $4s$-electrons in the interatomic metallic bonding.
In light of the above statements, choose the most appropriate answer from the options given below:

Which of the following alloys is used to make statues?

Among $Sc$,$Mn$,$Co$ and $Cu$,identify the element with the highest enthalpy of atomisation. The spin-only magnetic moment value of that element in its $+2$ oxidation state is $......... \text{BM}$ (in nearest integer).