Answer :
you have to find the differences of electronegativity for the atoms joined by the bond. if their diff is <0.4,
then it's non-polar if it's between 0.4 to 1.7
then it's polar 1.7 and up it's ionic Electronegativity values can be found on most periodic tables.
then it's non-polar if it's between 0.4 to 1.7
then it's polar 1.7 and up it's ionic Electronegativity values can be found on most periodic tables.