The magnetic moment of $M^{x+}$ (atomic number $= 25$) is $\sqrt{15} \ BM$. The number of unpaired electrons and the value of $x$,respectively,are

Assertion: In general,transition metals have high melting points.
Reason: More number of electrons from $(n-1)d$ and $ns$ are involved in interatomic metallic bonding.
The correct option among the following is

Match the species in List-$I$ with their correct electronic configuration in List-$II$.

List-$I$	List-$II$
$(1) \ \text{Cr}$	$(A) \ [\text{Ar}] \ 3d^8 4s^0$
$(2) \ \text{Fe}^{2+}$	$(B) \ [\text{Ar}] \ 3d^{10} 4s^1$
$(3) \ \text{Ni}^{2+}$	$(C) \ [\text{Ar}] \ 3d^6 4s^0$
$(4) \ \text{Cu}$	$(D) \ [\text{Ar}] \ 3d^5 4s^1$
	$(E) \ [\text{Ar}] \ 3d^6 4s^2$

What is the correct order of the theoretical magnetic moment for $Mn^{2+}$,$Cr^{2+}$,and $V^{2+}$?

Write down the electronic configuration of:
$(i) Cr^{3+}$
$(ii) Pm^{3+}$
$(iii) Cu^{+}$
$(iv) Ce^{4+}$
$(v) Co^{2+}$
$(vi) Lu^{2+}$
$(vii) Mn^{2+}$
$(viii) Th^{4+}$

Which of the following pairs of elements cannot form an alloy?