The number of ionic,covalent,and coordinate bonds in $NH_4Cl$ are respectively:

Which one of the following is a correct set?

The number of molecules or ions from the following,which do not have an odd number of electrons are $...............$.
$A. NO_2$ $B. ICl_4^{-}$ $C. BrF_3$ $D. ClO_2$ $E. NO_2^{+}$ $F. NO$

The correct order of increasing bond length of $C - H, C - O, C - C$ and $C=C$ is

The ionization enthalpy of $Na^{+}$ formation from $Na_{(g)}$ is $495.8 \ kJ \ mol^{-1},$ while the electron gain enthalpy of $Br_{(g)}$ is $-325.0 \ kJ \ mol^{-1}$. Given the lattice enthalpy of $NaBr_{(s)}$ is $-728.4 \ kJ \ mol^{-1}$. The energy for the reaction $Na_{(g)} + Br_{(g)} \rightarrow NaBr_{(s)}$ is $(-) \dots \dots \dots \dots \dots \times 10^{-1} \ kJ \ mol^{-1}$.

$CO$ has the same number of electrons as which of the following ions? Or,which ion is isoelectronic with $CO$?