Which of the following molecules is polar?

Question

NO2^−
CO2
CH3Cl
CO3^2−
ClO3^−

Is each either polar or nonpolar?
Could you kind of explain?
thank you

^ indicates start of superscript/ionic charge

Answer 1

The ones having an ionic charge....are definitely polar....or ionic.....but CO2.....is non polar due to its linear structure......
( O=C=O )
The polarity induced by one O atom...is equalled and cancelled by the other...........
CH3Cl......is polar......understandby its structure.........
H
|
Cl---C---Cl
|
Cl

Answer 2

NO2^− , CO3^2− , ClO3^−

Overall charge indicates polarity.

Answer 3

the iit kgp guy is right except that CH3Cl is polar too...
to find out which ones are polar, u can draw the structures of the molecules.. dipole moment in chemistry acts from the less electronegative atom to the more electronegative atom.. considering dipole moments as vectors, if in the molecule, the net dipole moment is not zero, then its polar.
if its 0, as in symmetric molecules, that is linear or tetrahedral molecules, the molecule is nonpolar.. so in ur question, all molecules are polar except CO2 which is linear n hence non - polar.