Question

What symbols are used to represent the charges on atoms in a polar covalent bond? What is the polarity of the bond?

Answer 1

Hint: In a polar covalent bond, one atom will more electronegative and the other will less electronegative so, the atom will more electronegative will be slightly negative and the other atom will be slightly positive.

Complete answer:
The covalent bond is formed when the atoms forming the bonds are non-metals and they cannot form ions like the bond between hydrogen and chlorine, oxygen and oxygen, nitrogen and hydrogen, etc. So, there are two types of covalent bonds, i.e., non-polar covalent bonds and polar covalent.
When two dissimilar non-metal atoms form a covalent bond then it is known as non-polar covalent bonds because there will differ in their electronegativity and this difference in the electronegativity will cause polarity in the bond. Due to this polarity, the electrons forming the bond will slightly move towards the more electronegative atom, this will create a partial negative charge on the more electronegative atom and partial positive charge on the less electronegative atom. This will be represented by the symbol delta ($\delta$), for the partial negative charge it is ${\delta }^{-}$ and for partial positive charge it is ${\delta }^{+}$.
Let understand this by an example:
In hydrochloric acid, there is a polar covalent bond because the electronegativity of chlorine is higher than the electronegativity of the hydrogen atom. This will be represented as:
$\stackrel{{\delta }^{+}}{H}-\stackrel{{\delta }^{-}}{Cl}$

Note:
If the bonds are formed between two same non-metal atoms like $O_2$, $N_2$, etc then the bond will not be a polar covalent bond because there is no difference in their electronegativities and are polar covalent bond.