Arrange the bonds in order of increasing ionic character in the molecules: $LiF$,$K_2O$,$N_2$,$SO_2$,and $ClF_3$.

Fill in the blanks given below:
$(i)$ The attractive force which holds atoms,molecules,and ions together is called ......... .
$(ii)$ First of all,............ and ............ scientists provided detailed information about valency.
$(iii)$ In the structure of an atom,when only the electrons of the outermost shell participate,they are known as ............ .
$(iv)$ The symbol used to represent valence electrons in an atom is called ........ .

In which of the following pairs is the geometry around the central atom not the same?

Calculate $x + y + z$ for $H_3PO_3$ acid,where $x$ is the number of lone pairs,$y$ is the number of $\sigma$ bonds,and $z$ is the number of $\pi$ bonds.

Bonds present in $CuSO_4 \cdot 5H_2O$ are

Which of the following sets are correctly matched?

Molecule	Hybridization	Geometry
$I$. $BrF_5$	$sp^3d^2$	Square pyramidal
$II$. $XeF_6$	$sp^3d^3$	Distorted octahedral
$III$. $SF_4$	$dsp^2$	Square planar
$IV$. $PbCl_2$	$sp$	Linear