In this compound, valency of A is 2 and valency of B is 4.

It is a polar molecule. The bond between carbon and hydrogen is considered non-polar, but the bonds between carbon and chlorine are considered polar covalent.

The valency in a formula can be explained on the cris-cross basis. Hence, the number of electrons in the outermost shells of A and B would be 5 and 2, respectively.

Elements do try to attain stable configuration by sharing, losing or gaining electrons.

It does not contain hydrogen bonds.

Ozone has bent geometry.

Depending upon the electronegativities of the sharing atoms, a shared electron pair may be attracted at varied degree between the two atoms. This results in a partial positive and negative charge upon them and results in a polar molecule. Ammonia is thus, polar in nature.

It is a covalent compound formed by the sharing of electrons between two hydrogen atoms.

The difference between electronegativities of hydrogen and fluorine is maximum. Hence, the hydrogen bonds are formed by hydrogen fluoride molecule.

Ammonia contains hydrogen bonds. Hence, its boiling point is high.

Na and Cl form an electrovalent compound. Hence, they are able to conduct electricity.

It contains all the three types of bonds.

As this element contains 7 electrons in the outermost shell, so it can accept one electron to form an electrovalent compound.

Electrovalent compounds are made up of negatively and positively charged ions.

Because ions are either positively charged or negatively charged, so these can be formed either by loss or gain of electrons.