Identify the ferromagnetic element from the following.

If a titanium compound exhibits a magnetic moment of $1.73 \, B.M.$,what is the oxidation state of $Ti$ in the compound?

The element which shows only one oxidation state other than its elemental form is:

Assertion : Transition metals show variable valency.
Reason : Transition metals have a large energy difference between the $ns^2$ and $(n-1)d$ electrons.

Fill in the blanks:
$(a)$ The shielding effect of $d$-electrons is ......... effective than $p$-electrons.
$(b)$ $A$ decrease in exchange energy leads to a ......... in stability.
$(c)$ The maximum oxidation state of $Mn$ is ..........
$(d)$ The stability of $Mo(VI)$ and $W(VI)$ is found to be .......... than that of $Cr(VI)$.

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