Non-polar atoms with lone pairs

[EvaLi_3J]

If a molecule has 1 lone pair, is it ever gonna be non-polar?
If it has 2 lone-pairs, can it be non-polar, since the lone pairs could possibly cancel each other?
If it has 3, 4, 5..., can it still be non-polar?

[Kate Osborne 1H]

Atoms with lone pairs can be non-polar, for example I2.

[Sharon Rodriguez 3H]

The majority of the time it is true that if a molecule has lone pairs, it will be polar. There are cases, like stated above, where molecules have lone pairs but are nonpolar. Remember to keep in mind the molecular geometry and dipole moments when considering this, there will always be exceptions so there is no straight answer but I hope this helps!

[TheresaDsilva4A]

I have a follow-up question: How can we tell that dipole moment vectors cancel when they are at angles to one another (e.g. in a molecule with trigonal planar geometry)? Do we have to break up the vectors into their individual components?

[Amanda Mei 1B]

I have a follow-up question: How can we tell that dipole moment vectors cancel when they are at angles to one another (e.g. in a molecule with trigonal planar geometry)? Do we have to break up the vectors into their individual components?

If all the bonds are between the same 2 atoms, they cancel out if the molecular is symmetrically arranged - no side has a more negative or positive charge than another. However, if there is a bond between the same central atom but a different atom, the difference in electronegativities will most likely be different, resulting in different dipole moments. Sometimes you'll need to consider the geometric shape of the molecule to determine if the the bonds are symmetrically arranged or not.