Question

In drawing Lewis structures, we learn that a hydrogen atom forms only one bond in a covalent compound. Why?

Short answer

Since a hydrogen atom has only one electron, it can make only one bond with another element. Its oxidation state can be either be -1, 0,or +1 depending onwhether the hydrogen receives, shares, or loses an electron.

Step-by-step solution

Definition of Lewis structures

The Lewis structures, also known as the Lewis dot formulas,are diagrams that show the bonding between the atoms of a molecule as well as the lone pairs of an electron that may exist in a molecule.

Reason why hydrogen forms only one bond

When the electronegativity of atoms is similar, an electron pair that isshared is equally attracted by both atoms, making this covalent bond non-polar.

The difference in the electronegativity of the two atoms is less than 0.5. However, when two atoms differ in their electronegativity by more than 0.5 but upto 1.7, an electron pair is closer to the atom with a higher value of electronegativity,so this covalent bond is polar.