Explain how covalent bonds are formed. Mention physical properties of covalent compounds. Draw the electron dot structure of $CCl_{4}$.

(N/A) covalent bond is formed when two atoms share valence electrons to achieve a stable noble gas electronic configuration,as they cannot gain or lose electrons from their outermost shell.
Physical properties of covalent compounds include:
$(i)$ They are generally poor conductors of electricity.
$(ii)$ They have low boiling and melting points due to weak intermolecular forces.
$(iii)$ They are generally soluble in organic solvents.
$(iv)$ They are typically found in liquid or gaseous states at room temperature.
In $CCl_{4}$,carbon has $4$ valence electrons and each of the four chlorine atoms has $7$ valence electrons. Carbon shares one electron with each of the four chlorine atoms to complete its octet,and each chlorine atom completes its octet by sharing one electron with carbon.