When will an atom form multiple covalent bonds?

Answer 1

When an atom has a valence number greater than one, it can form multiple covalent bonds.

For example, chlorine requires the gain of only 1 electron to form a stable configuration (being in Group 7 of the periodic table), and, therefore, only forms one covalent bond.

However, oxygen requires the gain of two electrons, and can form double bonds (such as in the case of carbon monoxide [C=O] and carbon dioxide [O=C=O]) or multiple single bonds (as in water [H-O-H]).

In the case of nitrogen (Group 5), it has 5 valence electrons, and requires the gain of 3 electrons to fill its valence shell. So, it can form:

- 3 single bonds (as in ammonia [NH3]);

- 1 single bond + 1 double bond (as in nitrous acid [H-O-N=O])

- 1 triple bond (as in hydrogen cyanide [HCN])

Note: This differs from ionic bonds formed by (metals + nonmetals), where electrons are completely transferred through large differences in electronegativities, forming ions, which are attracted through electrostatic attraction.

Answer 2

An atom will form multiple covalent bonds when it has more than one valence electron available for bonding. This allows the atom to share electrons with multiple other atoms to achieve a more stable electron configuration. Examples of such atoms include carbon, nitrogen, and oxygen.