Four bonded pairs

We refer to this as a pure covalent bond. Electrons shared in pure covalent bonds have an equal probability of being near each nucleus. This unequal distribution of electrons is known as a polar covalent bond, characterized by a partial positive charge on one atom and a partial negative charge on the other.

In every ionic compound, the total number of positive charges of the cations equals the total number of negative charges of the anions. Thus, ionic compounds are electrically neutral overall, even though they contain positive and negative ions.

Covalent bonds between identical atoms (as in H2) are nonpolar—i.e., electrically uniform—while those between unlike atoms are polar—i.e., one atom is slightly negatively charged and the other is slightly positively charged.

Carbon tetrachloride (chemical formula CCl4) is known to be a covalent compound since it features four nonpolar covalent bonds between carbon and chlorine.

4 bonding electron pairs

Some molecules contain a double or triple bond. This type of bond occurs when more than one pair of electrons are shared between the atoms to attain a full outer shell (double bond – 2 pairs of electrons, triple bond – 3 pairs of electrons). An example is carbon dioxide. This can be represented as 0=C=0.

C2H4 (Ethylene) consists of 2 carbon atom and 4 hydrogen atoms. The carbon-carbon bond is double covalent bond ie; sharing of two-electron pairs occurs. The valence electrons of carbon are 4 and that of hydrogen is 1.

tetrahedral geometry