Question

How do you determine the negative end of a dipole?

Answer 1

The negative end has the more electronegative element.

Answer 2

So the one with the larger number?

Answer 3

Like for water molecules, the oxygen is much more electronegative than the hydrogens, so the side with the oxygens are the negative ends of dipole-dipole interactions.

Answer 4

P-Cl
Which is the negative end

Answer 5

Chlorine has an electronegativity of 3.16 while Phosphorous has an electronegativity of 2.19, so Cl is the negative end.

Answer 6

If an element has a higher electronegativity, electrons are more strongly attracted to it. So electrons = more negative.

Answer 7

thanks

Answer 8

A usually correct and fast way to tell is by looking at the periodic table.

As you go from left to right, the number of electrons in the outer electron orbital increases. Since electrons are negatively charged, they will usually be your negative end of the dipole.

As you go from up to down, the total number of particles such as protons, neutrons, and electrons decreases, just consider how Hydrogen is a gas while Cesium is a solid in the same column. You could look at A as being a Cesium atom and B as being a Hydrogen atom.

Even though Cesium is larger than Hydrogen, the charge is spread out more in the Hydrogen, so you have a more electronegative atom. Cesium's protons and electrons are much closer together because of their strong attractions and in being so close they cancel out each other's charge more. It's similar to the difference between polar and nonpolar molecules but it's between subatomic particles instead of atoms.

Answer 9

So to be clear, the top right of the periodic table is more electronegative than the bottom left. But keep in mind it's only a common trend, there are some exceptions!