The number of $S-S$ bonds in sulphur trioxide trimer $S_3O_9$ is

Fill in the blanks given below:
$(i)$ The two theories based on the principles of quantum mechanics are ........ and ......... .
$(ii)$ The electronic configuration of carbon in the excited state is ........... .
$(iii)$ Through the combination of atomic orbitals,....... are formed.
$(iv)$ The ${\rm{CH}}_4$ molecule has a .......... shape.

The lattice energy of $NaCl$ is $-780 \, kJ \, mol^{-1}$. The enthalpies of hydration of $Na^{+}_{(g)}$ and $Cl^{-}_{(g)}$ ions are $-406 \, kJ \, mol^{-1}$ and $-364 \, kJ \, mol^{-1}$ respectively. The enthalpy of solution of $NaCl_{(s)}$ is $..... \, kJ \, mol^{-1}$.

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 is true?

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