Answer
There are 4 bonding pairs of electrons in the $SiCl_4$ molecule.
Work Step by Step
In the diagram, each bonding pair is represented by 1 line.
Therefore, looking at the Lewis symbol of $SiCl_4$ molecule on the right side, we witness 4 lines surrounding $Si$. That means there are 4 bonding pairs of electrons in the $SiCl_4$ molecule.
The reason for these 4 bonding pairs of electrons is that for each $Cl$ giving 1 electron for sharing, $Si$ would also gives 1 electron for sharing. Eventually, there would 4 bonding pairs of electrons for 4 $Cl$.
