Melting point of  $FeCl_3$  and  $FeCl_2$  is

How many unpaired electrons are there in $N{i^{2 + }}$

While filling up of electrons in the atomic orbitals, the $4s$ orbital is filled before the $3d$ orbital but reverse happens during the ionisation of the atom. Explain why ?

The statement that is $INCORRECT$ about the interstitial compound is

A first row transition metal with highest enthalpy of atomisation, upon reaction with oxygen at high temperature forms oxides of formula $\mathrm{M}_2 \mathrm{O}_{\mathrm{n}}$ (where $\mathrm{n}=3,4,5$ ). The 'spin-only' magnetic moment value of the amphoteric oxide from the above oxides is. . . . . . ..$\mathrm{BM}$ (near integer)

(Given atomic number: $\mathrm{Sc}: 21, \mathrm{Ti}: 22, \mathrm{~V}: 23$, $\mathrm{Cr}: 24, \mathrm{Mn}: 25, \mathrm{Fe}: 26, \mathrm{Co}: 27, \mathrm{Ni}: 28, \mathrm{Cu}: 29$, $\mathrm{Zn}: 30)$

Magnetic moment $2.84\, B.M.$ is given by (At. nos. $Ni = 28, Ti = 22, $$Cr = 24, Co = 27$)