Exceptions to the Octet

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005321227
Posts: 90
Joined: Sat Sep 07, 2019 12:15 am

Exceptions to the Octet

Postby 005321227 » Thu Oct 31, 2019 10:19 pm

How does P violate the octet rule? does it have a valence shell of 10?

SGonzales_3L
Posts: 55
Joined: Thu Jul 11, 2019 12:17 am

Re: Exceptions to the Octet

Postby SGonzales_3L » Thu Oct 31, 2019 10:43 pm

When P bonds with other atoms, it can expand its valence shells to accommodate more than 8 valence electrons. It actually has a valence shell of 5 electrons with the electron configuration [Ne]3s23p3. Since n=3, the atom now has d-orbitals which can accommodate more electrons, and so P and subsequent atoms can have expanded octets.

Melvin Reputana 1L
Posts: 55
Joined: Sat Aug 17, 2019 12:16 am

Re: Exceptions to the Octet

Postby Melvin Reputana 1L » Thu Oct 31, 2019 11:28 pm

Phosphorus is in the third period of the Periodic table. P-block elements in the third period and in later periods have access to the d-orbital which allows such elements to expand their valence shells. This is due to how these elements have empty d-orbitals in their valence shell.

SMIYAZAKI_1B
Posts: 63
Joined: Sat Aug 24, 2019 12:15 am

Re: Exceptions to the Octet

Postby SMIYAZAKI_1B » Fri Nov 01, 2019 2:47 am

Even though it is not shown, Phosphorus is in the 3rd shell which also has 3d10 as a part of it. Therefore, because Phosphorus's valence electrons end at 3p shell, we can also place electrons into the 3d shell which allows phosphorus to carry ten more electrons in its outer shell.

Junwei Sun 4I
Posts: 125
Joined: Wed Oct 02, 2019 12:16 am

Re: Exceptions to the Octet

Postby Junwei Sun 4I » Fri Nov 01, 2019 9:22 pm

Phosphorous violates the octet rule since it can have an expanded octet. P is in the third period on the periodic table, which means it has d-orbital that can accommodate extra electrons.For example when P bonds with Cl forming PCl5, the central atom P would have a total of 10 electrons, which violates the octet rule.

Abigail_Hagen2G
Posts: 107
Joined: Fri Aug 09, 2019 12:17 am

Re: Exceptions to the Octet

Postby Abigail_Hagen2G » Sat Nov 02, 2019 1:54 pm

Only a few elements really need to form an octet, because after that you reach the d-orbital, the 18-electron rule becomes apparent


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