What Is Polarity in Chemistry?
In chemistry, polarity describes the covalent bonds that occur between particles when two atoms unequally share an electron. Learn how water is the perfect example of negative polarity substance with information from a science teacher in this free video on science and chemistry.
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Hi, I'm Brian with ericksontutoring.blogspot.com. Today, we're going to discuss polarity in chemistry. So polarity is a principle that applies to bonding, and in particular, it describes the unequal sharing of electrons in a covalent bond. So covalent bonds -- if you remember or need explaining, covalent bonds are when two atoms share an electron. And the term electronegativity is used to describe sort of the pull or amount of attraction that an atom has for electrons. In general, electronegativity increases as you move to the right on a periodic table, as well as as you move up a periodic table. So polarity occurs when you have a difference in those electronegativities of less than 1.7. And basically, the result is that part of your molecule ends up being partially negatively charged because it is sort of an electron hog. It's holding the electrons close to it for...basically, it's hogging the electrons. And the other part of your molecule is going to be partially positively charged because it's not quite getting as much of the electrons as might be...might otherwise get if it weren't bonding. So let's use water as an example. Water is made up of oxygen and two hydrogens. They bond together. The oxygen also has four additional electrons that it keeps to itself. But oxygen has an electronegativity greater than that of hydrogen, so oxygen tends to pull the electrons and hog them closer to itself. The net result is that the oxygen part of water is slightly negatively charged, and the hydrogen parts of water are positively charged. The end result of this polarity is that water molecules are attracted to each other, and as well as other polar molecules. So that's a discussion of polarity in chemistry.