The bond length $(pm)$ of $F_2$, $H_2$, $Cl_2$ and $I_2$, respectively is

Give reasons for the following:
$A$. Covalent bonds are directional bonds while ionic bonds are non-directional.
$B$. Water molecule has bent structure whereas carbon dioxide molecule is linear.
$C$. Ethyne molecule is linear.

Which of the following does not obey the octet rule?

In the formation of a molecule by atoms,which forces operate?

Consider the following compounds:
$I. H_3X-NCS$
$II. H_3Y-NCS$
$III. (H_3X)_2O$
$IV. (H_3Y)_2O$
The incorrect statement regarding the given compounds is:

Assertion : Bond angle of $H_2S$ is smaller than $H_2O$.
Reason : Electronegativity of the central atom increases,bond angle decreases.