Question

Which statement is true?
A. a molecule having a covalent bond can be ionic
B. a molecule having a covalent bond is always polar
C. a molecule having a covalent bond may be polar or nonpolar
D. a molecule having a covalent bond i =s always nonpolar

Answer 1

A molecule with a covalent bond is always polar:

CF4 disproves this and let's try to understand why. In CF4 is obviously tetrahedral but for this to happen, there must be a net dipole moment, for the molecule to be polar, but when you draw it out the dipoles cancel, making it non-polar.

Answer 2

A molecule having a covalent bond can be ionic.

Poly atomic ions involve a sharing of electrons covalent and gaining/losing of electrons (ionic) to fulfill their octet. Take sodium carbonate for example. Na2CO3, contains both type.

Answer 3

thank you! @Photon336