octet rule

Moderators: Chem_Mod, Chem_Admin

Agustina Santa Cruz 2F
Posts: 88
Joined: Wed Sep 30, 2020 10:01 pm

octet rule

Postby Agustina Santa Cruz 2F » Sun Nov 15, 2020 6:10 pm

Why does Cl get 18 octet electrons?

LarisaAssadourian2K
Posts: 77
Joined: Wed Sep 30, 2020 9:34 pm

Re: octet rule

Postby LarisaAssadourian2K » Sun Nov 15, 2020 6:13 pm

Cl has a total of 17 electrons in different shells. To fill its valence shell (which has 7 electrons) and have a total of 8 electrons (to follow the octet rule), it would need to have a total of 18 electrons.

Taha 2D
Posts: 75
Joined: Wed Sep 30, 2020 9:50 pm

Re: octet rule

Postby Taha 2D » Sun Nov 15, 2020 6:19 pm

these arent octet electrons. in the case of an expanded octet a valence shell can hold more than 8 electrons if they have the subshells available(as in the case of sulfur in s03. to understand look at the periodic table. chlorine falls unders group 17 and period 3. n=3 means quantum number L can be 0,1,2. this means chlorine has subshells s,p,d. so in its third shell we can have 3s2,3p6,3d10=18.

Sean Wang 1F
Posts: 85
Joined: Wed Sep 30, 2020 9:34 pm

Re: octet rule

Postby Sean Wang 1F » Sun Nov 15, 2020 6:20 pm

You need 2 electrons to fill the first period, 8 electrons to fill the second, and 8 more to fill the third. Since Cl is in the third period, 2+8+8=18.

Susanna Givan 2B
Posts: 61
Joined: Thu Feb 27, 2020 12:16 am

Re: octet rule

Postby Susanna Givan 2B » Sun Nov 15, 2020 11:42 pm

can someone revisit the octet rule conceptually again?

305572629
Posts: 86
Joined: Wed Sep 30, 2020 9:41 pm

Re: octet rule

Postby 305572629 » Sun Nov 15, 2020 11:44 pm

Cl can expand its octet, but it actually only has 7 valence electrons normally. It has 17 electrons total, and to complete its octet it tries to obtain one more electron normally.

Eve Gross-Sable 1B
Posts: 87
Joined: Wed Sep 30, 2020 10:02 pm
Been upvoted: 1 time

Re: octet rule

Postby Eve Gross-Sable 1B » Sun Nov 15, 2020 11:54 pm

Susanna Givan 1L wrote:can someone revisit the octet rule conceptually again?


The octet rule says that atoms prefer to have eight electrons in their valence shell, and if they don't have eight, they will react with others to form stable compounds. I found this link gives a pretty good explanation https://chem.libretexts.org/Bookshelves ... _Chemistry)/Electronic_Structure_of_Atoms_and_Molecules/Electronic_Configurations/The_Octet_Rule

Andrew Yoon 3L
Posts: 87
Joined: Wed Sep 30, 2020 9:36 pm

Re: octet rule

Postby Andrew Yoon 3L » Sun Nov 22, 2020 12:53 pm

Cl has 17 electrons. It has 2 electrons in the first shell, 8 in the second shell, and 7 in the valence shell. The octet rule states that atoms will have 8 electrons in its valence electron. Cl will need one more electron to fill the valence shell and complete the octet rule. So 17 + 1 = 18 electrons.

Carly_Lipschitz_3H
Posts: 93
Joined: Wed Sep 30, 2020 9:56 pm

Re: octet rule

Postby Carly_Lipschitz_3H » Sun Nov 22, 2020 4:44 pm

Cl doesn't get 18 octet electrons, it will have 18 electrons overall. Since Cl has an expanded octet, its valence shell can hold more than the normal 8 electrons if there are subshells that can take these electrons. Since Cl has 17 electrons, it needs one more to complete its valence shell to get it to 18 electrons. Since Cl is in the n = 3 shell, it can have electrons to place into the 3 d shell.


Return to “Octet Exceptions”

Who is online

Users browsing this forum: No registered users and 1 guest