Polar/non-polar bonds vs molecules

[Jenny Chau 1I]

I don't know if I missed this during lecture or something but what's the difference between polar/non-polar bonds and molecules?

[dana hu 1B]

hello! the main difference between polar and nonpolar bonds is that polar bonds occur between elements with different electronegativity whereas non-polar bonds occur between with the same electronegativity.

[Bailey Giovanoli 1L]

So, essentially a polar bond is a bond where the electrons are not shared equally. You can tell this by looking at the electronegativity of the individual atoms. The higher the electronegativity difference between the two atoms the more polar the bond is. In terms of the polarity of a molecule, it's the same idea. If a molecule has a bunch of polar bonds and they do not cancel based on the arrangement, it is a polar molecule.

[Gina Spagarino 3G]

If a symmetrical molecule has all polar bonds, but of the same element, it is a nonpolar molecule . So, the B--F bond in BF₃ is polar because of F's higher electronegativity, but the molecule itself is nonpolar. If the charges cancel (which only happens with symmetrical shapes), the molecule is nonpolar.

[Shreya Patel- 2D]

It is also important to remember that polar bonds does not mean a molecule is polar. For example, in BeCl2 the molecule is nonpolar but the Be-Cl bonds are polar.

[Brian Nguyen 2I]

Polar bonds are formed based on if there is a notable difference in electronegativity between two elements within a molecule. Polar molecules are formed when the dipole moments formed due to polar bonds don't cancel out. If they do cancel out, then these molecules are nonpolar.