octet rule

[Agustina Santa Cruz 2F]

Why does Cl get 18 octet electrons?

[LarisaAssadourian2K]

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]

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]

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]

can someone revisit the octet rule conceptually again?

[305572629]

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]

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]

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]

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.