Which among the following statements is incorrect for interstitial compounds?
$1$. They are very hard and rigid
$2$. They have higher melting point than pure metal
$3$. They do not show conductivity
$4$. They are chemically inert

Which of the following is a product of the first step and is used as a reactant in the next step for the manufacture of $K_{2}Cr_{2}O_{7}$ from concentrated chromite ore?

Consider the following reactions:
$K_2Cr_2O_7 + NaCl + H_2SO_4 \rightarrow CrO_2Cl_2 + \text{Side Products}$
$CrO_2Cl_{2(Vapour)} + NaOH \rightarrow B + NaCl + H_2O$
$B + H^+ \rightarrow C + H_2O$
The number of terminal $'O'$ atoms present in the compound $'C'$ is $..........$

An acidified manganate solution undergoes disproportionation reaction. The spin-only magnetic moment value of the product having manganese in higher oxidation state is $....\, B.M.$ (Nearest integer)

Give the formulas of the oxocations of the $3d$ series metals.

Which metal oxide is used to make blue glass?