The formal charges on the atoms marked as $(1)$ to $(4)$ in the Lewis representation of $HNO_3$ molecule respectively are

Which of the following statements regarding $BCl_3$ is incorrect?

What is the limitation of the framework model?

What is the formal charge on the $C$ atom in the structure $S \equiv C - \ddot{N} :$?

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 ........ .

Compare $\pi$-bond strength between $B$ and $N$ in the following compounds: $(I)$ $((CH_3)_3Si)_2N^{-}BH_2$ and $(II)$ $((CH_3)_3C)_2N^{-}BH_2$.