What is the difference between polarity and polarization

Laurence Lavelle Skip to content. Quick links. Email Link. These two types depend on however the antenna is oriented in relation to the earth. Waves and antennas can also be circularly or elliptically polarized. In both circular and elliptical polarizations, the electric field spins along a fixed axis over time, sort of like twisting the flat ribbon mentioned above.

Here is a video that demonstrates polarization. Helical antennas are the most frequently encountered circularly polarized antennas. The Spotlight antenna is elliptically polarized. Wave polarization is hard to visualize. This video by Youtube user "Ruff" does a great job of illustrating the concept. Polarization is extremely important to the deployment of wireless audio systems.

It only takes a minute to sign up. Connect and share knowledge within a single location that is structured and easy to search. How do the terms polarity and polarizability differ from each other? In my opinion, polarity is the degree of ionic character in covalent compounds and polarizability implies towards degree of covalent character in ionic compounds.

Am I correct? Polarity refers to the distribution of partial electric charge in molecules or even materials. Or, more technically, the degree to which a molecule has a dipole moment which relates to its inherent electric field. Some molecules, like benzene, are non-polar as they have no net dipole moment; others, like nitromethane, have a strong dipole moment.

Polarity is a fixed property of the molecule that doesn't depend on the external field. Polarisability refers to the degree to which the electron clouds in a molecule or atom can be influenced by an external electric field.

Everything, polar or not, has a polarisability. Note: It's important to realize that this is an average picture. The electrons are actually in a molecular orbital, and are moving around all the time within that orbital. This sort of bond could be thought of as being a "pure" covalent bond - where the electrons are shared evenly between the two atoms. That means that the B end of the bond has more than its fair share of electron density and so becomes slightly negative.

At the same time, the A end rather short of electrons becomes slightly positive. A polar bond is a covalent bond in which there is a separation of charge between one end and the other - in other words in which one end is slightly positive and the other slightly negative. Examples include most covalent bonds. The hydrogen-chlorine bond in HCl or the hydrogen-oxygen bonds in water are typical. If B is a lot more electronegative than A, then the electron pair is dragged right over to B's end of the bond.

To all intents and purposes, A has lost control of its electron, and B has complete control over both electrons. Ions have been formed. The bond is then an ionic bond rather than a covalent bond. The implication of all this is that there is no clear-cut division between covalent and ionic bonds.

In a pure covalent bond, the electrons are held on average exactly half way between the atoms. In a polar bond, the electrons have been dragged slightly towards one end.

How far does this dragging have to go before the bond counts as ionic? There is no real answer to that. Sodium chloride is typically considered an ionic solid, but even here the sodium has not completely lost control of its electron. Because of the properties of sodium chloride, however, we tend to count it as if it were purely ionic.

Lithium iodide, on the other hand, would be described as being "ionic with some covalent character". In this case, the pair of electrons has not moved entirely over to the iodine end of the bond. Lithium iodide, for example, dissolves in organic solvents like ethanol - not something which ionic substances normally do. In a simple diatomic molecule like HCl, if the bond is polar, then the whole molecule is polar. What about more complicated molecules?

Consider CCl 4 , left panel in figure above , which as a molecule is not polar - in the sense that it doesn't have an end or a side which is slightly negative and one which is slightly positive. The whole of the outside of the molecule is somewhat negative, but there is no overall separation of charge from top to bottom, or from left to right.

In contrast, CHCl 3 is a polar molecule right panel in figure above. The hydrogen at the top of the molecule is less electronegative than carbon and so is slightly positive.

This means that the molecule now has a slightly positive "top" and a slightly negative "bottom", and so is overall a polar molecule.