Valence Shell Electron Pair Repulsion Theory (Simplified)

vance Shell electron propulsion theory, short named vesper theory, says that the geometry of a molecule is based on minimizing the repulsion okay, between electron groups on the central element. Now, what exactly do we mean by electron groups? While electron groups were going to say equal lone pairs on the central element plus bonding groups. Now, when I say bonding groups, I mean the surrounding elements that are connected to the central element. And we're going to say here that are lone pair electrons, which are part of our lone pair exhibit an electron cloud. That further adds to repulsion. Okay, so when we talk about vesper theory, it's just talking about atoms and lone pairs on the central element will space themselves out to form specific types of shapes. This helps this happens because of the repulsion it exists between the lone pairs and the bonding groups on the central element.

Here it asks how many electronic groups on the nitrogen atom based on the following lewis. So here we have NH three. Remember your electron groups equals the lone pair or pairs on the central element, plus the bonding groups on the central element. Remember Bondi groups are just these surrounding elements. So if we take a look here, we have one long pair on the central element Plus 1, 2, 3 surrounding elements, which equates to three bonding groups. So the total number of electron groups on the nitrogen would be four.

here, we can say using desperate theory, the locations of surrounding elements and lone pairs around the central element are determined here. We're going to say that the number of electron groups on the central element can either be 23 or four. If we take a look here at our molecular shapes, we're going to say when your central element has two electron groups, they both are going to be surrounding elements. So this black ball here represents our central element and it's connected to two surrounding elements for bonding groups. When we have three electron groups on the central element, there's two possibilities. The central element either has three Surrounding elements or it has two surrounding elements and one lone pair. When the central element has four electron groups, then there are three possibilities. The central element could either be connected to four surrounding groups and that's it. Or it can be connected to three surrounding groups and one lone pair. Or it could be connected to two surrounding groups and two lone pairs. So just realize the different combinations that exist and realize the more electronic groups that we have on the central element, the more the possible shapes that can arise. Now, all you have to remember our electron groups of 23 and four. So don't worry about going beyond that. And just remember we're going to go more in depth in terms of naming of these molecular shapes Later on

How many electron groups lone pairs and bonding groups does the compound have, respectively? Alright, so electron groups were going to abbreviate as E. G, lone pairs on the central element as LP and bonding groups as B. G. All right, so long pairs on the central element, we have one lone pair on the central element, Bonding groups are the surrounding elements attached to that central element. There will be one two bonding groups. That means we have a total of three electron groups. All right, so we say we have three electron groups, one lone pair add to bonding groups for this particular compound.