How Many Bonds Can Oxygen Form

Introduction

Oxygen can only form 2 bonds. Every atom, molecule, compound etc tends to move towards stability. Stability is defined as the lowest energy possible for their existence. Elements tend to be the most stable when their valency is complete i.e when they contain either 2 electrons in the case of hydrogen or 8 electrons in the case of other atoms with higher shell orbitals. This is known as the octet rule. The atoms also complete their octet or attain stability by forming covalent bonds. A covalent bond is referred to as sharing of electrons between 2 atoms. The atoms that are deficient in electrons share their electrons in order to achieve octets. Each bond is composed of 2 electrons. Formation of bonds is the easiest way for an atom to complete its octet and thereby acquire stability. This is the reason some elements are not found in the free state in the environment; they always exist in a combined form as molecules. Examples include H2, N2, O2.

Explanation

• Oxygen has an atomic number of 8. This implies that it has 6 electrons in its outermost shell. 2 electrons less than the stable configuration i.e 8. Now in order for the oxygen atom to achieve octet and stability it needs to acquire 2 more electrons.

• So for the oxygen atom to achieve its octet, one of the lone pairs among the 3 lone pairs contained in its outermost shell forms a bond to accomplish a configuration of 8. Since each bond is composed of 2 electrons, in order to complete its octet 2 bonds will be formed by 2 electrons of the oxygen.

• It can be understood as oxygen giving or sharing 2 of its electrons with the other atom to gain 2 of the other atom's electrons resulting in the formation of 2 bonds thereby making the outermost shell a complete octet.

• Since after the formation of 2 bonds, the octet is complete and the oxygen cannot accommodate any more electrons in its shell therefore when it forms a third bond it gains a positive charge implying that it is not capable of sharing electrons it can only donate one of its electrons to the other atom making the oxygen itself electron deficient.

• This deficiency in oxygen results in the rise of resonance which is an electron-sharing phenomenon wherein the π electrons get delocalised and move from one oxygen atom to the other thereby simultaneously completing the octet.

• This is observed in the case of O3 molecules.

Conclusion

• All atoms follow the octet rule.

• The octet rule emphasises the completion of 8 electrons in an atom's valence shell.

• The oxygen already contains 6 electrons in its outermost shell

• Therefore it can only form 2 bonds which complete its octet

• After the formation of 2 bonds no more vacant orbital is available for the accommodation of electrons.