Define polar covalent bond and non polar covalent bond.
Answers
covalent bond- covalent compounds are said to be non polar when shared pair of electrons are equally distributed between the two atoms.
In a covalent bond, two atoms of non metals are bonded.
The electrons in that molecule are shared equally. In a covalent bond of two same types of atoms or the molecule of that atom, both atoms share the electrons at an equal distance as they both will have the same electronegativity and the difference of both the electronegativities of both atoms is 0. This type of bond is known as a non polar bond.
Ex. In a H2 molecule, the structure will be as such :
H -:- H
The dots are the electrons. Since each hydrogen atom will contribute 1 electron, they both will share a helium configuration. The electrons are at a equal distance from both the atoms.
In a molecule of two different atoms, where the difference of electronegativities between the two atoms is greater than 0 and less than 1.7 the shared pair of electrons will be attracted towards the more electronegative element as the more electronegative an element is, the more tendency it has to pull electrons towards it. This type of bond formation is known as a polar covalent bond.
Ex.
H2O :
the electrons in a H2O molecule are closer to the oxygen atom as electronegativity of oxygen is 3.44, while the electronegativity of hydrogen is 2.1 . So, the electrons will be attracted towards the oxygen atom. Hence it is a polar molecule.
Hope it helps!