Molecular Polarity

When it comes to the idea of molecular polarity, we have to take into account perfect shapes versus non perfect shapes or imperfect shapes. We're going to stay here first recall that polarity of chemical bonds arises from unequal sharing of electrons between atoms based on electro negativity. Remember elements that are more electro negative will tend to attract electrons more towards themselves. Now we're going to say the molecular molecular polarity itself is just the polarity that arises for an entire molecule. And we're gonna say here we have non polar molecules and polar molecules as a result. Now, when we say non polar molecules were saying this is any hydrocarbon so composed of only carbon and hydrogen and any non hydrocarbon with the perfect shape. Now, when we say perfect shape, we break it down into perfect shape one versus perfect shape too. Now for perfect shape one, this is when our central element has the same surrounding elements and it has zero too long pairs. So you're central element has no long pairs on it. Our perfect shape to this happens when are central elements still has the same surrounding elements and it's either linear or square planner or planner. Okay, so that's the additional caveat for perfect shape too, we're going to say here that a polar molecule is any lewis dot structure that doesn't have a perfect shape. So if you're able to identify a perfect shape automatically, it's going to be non polar. And if you have a molecule that doesn't fit fit perfect shape one or two, it's by default polar

So remember if you are a perfect shaped one or perfect shape to you're going to be non polar by default. So if we take a look here, we have our number of electron groups around our central element. Remember an electron group is either a surrounding element or a lone pair on that central element. They're both classified as electron groups and our central element can either have zero lone pairs all the way up to three lone pairs. Now, if we take a look here, all those that are sheeted in green represent perfect shape Once all of them have a central element that is the black sphere and all of them have the same surrounding elements around them. And most importantly, the central element has no lone pairs. Okay, so everyone here in this ring column would be non polar here. If we look at these two orange backgrounds, we're gonna say those are also non polar because they represent are perfect shape. Twos they have our central element in the center and we have the same surrounding elements. So we're gonna assume that these fears here are the same surrounding elements and they are either linear. So this would be a linear shape or they are square, planner or planner. So they fit the whole idea of perfect shape too. That's why there are also non polar. The other ones that are not highlighted. If you have those shapes, there's no way we can make them non polar. They're always going to be polar molecules. All right. So if you get anything that's within this part here, which is not shaded in green or an orange, they're always going to be polar. So keep that in mind. Look to see if your molecule has a perfect shape, one or perfect shape, too. If it doesn't fit the criteria, it's non polar. If it doesn't, then it's going to be polar.

here in this example question, it says determine of carbon tetrachloride, which is CCL four is poor or non polar. Alright, so here, remember when we draw lewis dot structures, we place the least electro negative element in the center. In this case it would be carbon carbon here is in Group four A. So it has four valence electrons. So we're gonna draw our four valence electrons, Our chlorine, our in group seven a. So they each have seven valence electrons. Oh and remember carbon wants to make four bonds or must make four bonds. So each chlorine will form a single bond with our carbon. Now, if we take a look at the structure, we're going to say that our central element has the same surrounding elements and it has no lone pairs on it, it would be defined as a perfect shape one and as as a result of being a perfect shape, it would be non polar. So if you were going to say that carbon tetrachloride is a non polar molecule.