Polar and Nonpolar

[Aimee Alvarado 3J]

I usually know if a molecule is polar or nonpolar depending on if there is an unequal or equal sharing of electrons, but would I need to do more to make sure?

[Taha 2D]

Depends on their shape as well and if the dipoles cancel or not

[Susan Chamling 1F]

It helps to take into account the 3D shape of the molecule rather than just the Lewis structure, as the Lewis structure may lead us to believe it is nonpolar when it is actually polar, and vice versa. Sometimes I will look at the symmetry of the forces acting on the molecule, because if it is symmetrical it is most likely nonpolar since the forces cancel out.

[Sheryl Ocampo 1D]

The symmetry of the molecule also plays a role in polarity as the partial charges could cancel each other out

[Astha Patel 2J]

The shape of the molecule can show whether dipoles are positioned to cancel each other out.

[alexandralopez 3F]

You have to take into account the shape and see what the pull is like (if the dipoles cancel)

[Kushaal Madadi 2F]

It is important also to consider whether the shape of the molecule and the arrangement of the atoms causes the dipoles to cancel!

[Fernanda Olvera 3D]

I agree, ^ the shape and dipoles are taken into account to determine if it is polar/nonpolar.

[Teti Omilana 1G]

You also can draw the lewis structure for the molecule and look for asymmetry. If it is asymmetrical, it's polar and if it's symmetrical it's non- polar.

[Sam Wentzel 1F 14B]

Yes. You should memorize which molecular shapes are symmetrical, and thus non-polar assuming that the dipoles cancel, and which one's are not. Symmetrically shaped molecules will tend to be nonpolar, asymmetrically shaped molecules will tend to be polar. Hope this helps!

[Gabriel Nitro 1E]

Hi,

You should also take into account the shape of the molecule as the asymmetry/symmetry may cancel out polar bonds.

Hope this helps! :)

[105618850]

You would also need to consider if the dipole moments, if there are any, cancel each other out.

[Jordan Tatang 3L]

I usually draw the dipole moments to see if they cancel or not.

[Charlotte Adams 1A]

Drawing the shape of the molecule and the dipole moments will help because it will show if the dipole vectors cancel out.

[Jasraj Parmar 3H]

You have to look at the shapes and see if the dipole force cancel each other out. If they cancel out each other than it is non-polar. If they don't cancel out they are polar.

[Adrienne Yuh 2B]

I like to draw out the figure and arrows pointing in the dipole directions. Memorizing what cancels what is really helpful.

[Nancy Yao]

The dipoles are like vectors and sometimes they cancel out each other.

[Annette Fishman]

It becomes way easier when you draw the molecule and draw out the vectors to signify the dipoles! If they cancel out, the molecule is nonpolar.

[Edwin Liang 1I]

Drawing the molecule and seeing whether there is a difference in dipoles helps too

[Brenda Silva 1B]

The shape of the molecule and the difference in dipoles are also important to figure out whether a molecule is polar or non-polar. If the dipole forces cancel out then the molecule is non-polar.

[Allan Nguyen 2G]

Don't forget that a molecule can have polar bonds but can still be a nonpolar molecule due to its shape.

[Margaret Xu 3C]

In order to consider if a molecule is polar or nonpolar, I always draw the Lewis structure first to see if the dipoles cancel out of it there are lone pairs.

[Rose_Malki_3G]

Check to see if the dipoles cancel it. If they do, then the species is non polar and if they do not cancel out, the species is polar.

[Emma Ide 2E]

The shape can indicate if the dipoles cancel or not. Polar molecule's dipoles do not cancel.

[Hailey Qasawadish 2J]

I also like to see what the shape is in order to determine if it is polar or nonpolar. A lot of times, you can determine polarity by looking at if there are lone pairs or not. If there are lone pairs, it is usually polar.

[Morgan Gee 3B]

Understanding the 3D model of the lewis structure is important too, as 2D images may be misleading. A common example is the linear molecular geometry from a trigonal bipyramidal electron geometry (AX2E3). While it may appear to be polar because of the asymmetrical lone pairs, it is still considered to be a polar molecule.

[CesarLec1]

A good thing to do if you have time is to draw the lewis structure of the formula and check to see if the bonds are polar and nonpolar to see if it all cancels out. If the central atom however, it surrounded by atoms that are all the same in symmetrical positions then all the polarity should cancel out.

[Jeremy Wei 2C]

Hi, what I normally do is that I draw out the 3D structure of the molecule and seeing if the dipole moments cancel out.

[Algernon Jackson 2l]

You have to also look at the shape and the dipoles.

[Joseph Liao 3C]

Honestly, polarity confuses me sometimes too, especially when I'm just given the formula of a molecule and asked if it is polar or not. What helps me a lot is drawing out the molecule and seeing how the dipoles work out; if they cancel out, then you know it is non-polar!

[Emily Wan 1l]

You would have to first determine if the bonds in the molecule are polar or non-polar (look at differences in electronegativity.) If there are polar bonds in the molecule, the shape and symmetry of the molecule should then be considered. You can draw arrows showing the dipole moments and see if they are able to cancel out.

[Shreya Arcot 3K]

If you are given the electronegativities of the atoms in the molecule, you can see whether it's polar or nonpolar. Polar molecules have a large difference in electronegativity, whereas nonpolar molecules have similar/same electronegativity values.

However, electronegativity values are usually not given. So, you can look at the 3D shape of the molecule to determine its polarity.

[Arad_Badiee_2B]

Just wanted to add an example along with what everyone else said. Visually considering the molecule, something like CH4 would be non-polar, and understanding that it has a symmetric tetrahedral structure would indicate such. However, H2O, being non-symmetric, can be deemed as polar.

[Madelyn_Rios_2c]

It helps to draw the molecule and see if dipoles cancel.

[Samantha Quevedo 2L]

You can draw out the structure of the molecule and see if the dipoles cancel out! You can also determine its polarity based off its electronegativity.

[Helen Ringley 2E]

Since different "lobes" of the shape show the general location of electrons, if the atom isn't symmetrical then there is an uneven charge, which can cause it to be polar.

[Harbaksh Kaur 3E]

That's a great place to start! I would also recommend to look at the shape and see if the dipoles cancel out!

[Alaura Dis 1H]

Hi, the shape of the molecule also should be taken into account when determining the polarity of the molecule. A good way to look at this is to draw out the molecule and compare the dipoles to see if they cancel out.