Xe Lewis Dot Structure

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104607508
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Joined: Fri Sep 25, 2015 3:00 am

Xe Lewis Dot Structure

Postby 104607508 » Sun Oct 11, 2015 2:42 pm

I understand the rule behind drawing Lewis Dot Structures and the general need for various atoms to follow the octet rule which renders them more stable, but what i don't understand is why an element like Xe can form bonds with 6 fluorides and still have an extra two electrons because I'm not sure if that follows the octet rule. Also, are the any more elements that don't follow the octet.

LinaLi2E
Posts: 22
Joined: Fri Sep 25, 2015 3:00 am

Re: Xe Lewis Dot Structure

Postby LinaLi2E » Sun Oct 11, 2015 3:27 pm

The reason why Xenon can bond to 6 Fluorines is because it is an exception to the octet rule. Some elements in period 3 or high can hold more than an octet due to the 3d orbitals that are available for electrons to be added. These elements that are exceptions can have up to 10, 12, or 14 electrons in the outer shell, around the center atom when they are forming bonds. There are also elements that can have less than 8 electrons and be stable too. So, Xenon is an exception. Also, Xenon is a noble gas, which do not usually form bonds but if you follow the trends on the periodic table, you will notice that Xenon is pretty far down the group. As you move down the periodic table, the atomic radius gets bigger. Since Xenon is pretty far down, that means that the radius is large, so the outermost electrons are relatively far away from the nucleus, where the positive attraction is. Due to the atomic radius, the attraction of the outer valence electrons and the nucleus is not as strong, so Xenon can form bonds with other elements. Xenon is in period 5, with a large radius and Flurine is very electronegative so the compound XeF6 can be formed.

Joyce Xiong 4C
Posts: 22
Joined: Fri Sep 25, 2015 3:00 am

Re: Xe Lewis Dot Structure

Postby Joyce Xiong 4C » Sun Oct 11, 2015 3:41 pm

After finding your question, I researched about the octet rule, and there are actually a lot of exceptions to the octet rule that we have yet to cover. Once we go beyond n=3, there is something called the "expanded octet" that has to do with elements with d orbitals who can have more than one octet. I found this youtube video that explains the case of Xenon HexaFluoride, which is actually called a noble gas compound.

https://www.youtube.com/watch?v=ScTz6KZXbBY
He starts explaining Xenon HexaFluoride at 4:05 and talks about the general exception of so-called "expanded octets" at 4:55. I hope the video can help clarify your question at least a little bit!


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