Seesaw vs. trigonal pyramidal

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Shannon Moore 2L
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Seesaw vs. trigonal pyramidal

Postby Shannon Moore 2L » Wed Dec 09, 2020 6:05 pm

Are seesaw and trigonal pyramidal the same shape? I am confused

Ashley Ko 3I
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Joined: Wed Sep 30, 2020 9:54 pm

Re: Seesaw vs. trigonal pyramidal

Postby Ashley Ko 3I » Wed Dec 09, 2020 6:08 pm

No, while seesaw has 5 regions of high electron density, trigonal pyramidal only has 4 regions of high electron density. Hope this helps!

IsaacLaw1E
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Re: Seesaw vs. trigonal pyramidal

Postby IsaacLaw1E » Wed Dec 09, 2020 6:08 pm

No. Trigonal pyramidal is when you make one of the bonding pairs on a tetrahedral shaped molecule a lone pair, so there are three bonding pairs connected to a central atom with bond angles of a <109.5deg.
Seesaw is when you remove one bonding pair from the equatorial of a trigonal bipyramidal and make it into a lone pair. It has four bonding pairs connected to a central atom, with bond angles of 90 and 120.

Anna_Mohling_1D
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Re: Seesaw vs. trigonal pyramidal

Postby Anna_Mohling_1D » Wed Dec 09, 2020 6:09 pm

Hi, they are not the same! See saw has 1 lone pair and 4 bonding pairs and trigonal pyramidal has 1 lone pair and 3 bonding pairs.

Brandon Pham 1H
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Re: Seesaw vs. trigonal pyramidal

Postby Brandon Pham 1H » Wed Dec 09, 2020 6:10 pm

What Ashley said was correct, and:
-See-saw has bond angles of <90 and <120
-Trigonal pyramidal has bond angles of <107.5

Taber Ball 1F
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Re: Seesaw vs. trigonal pyramidal

Postby Taber Ball 1F » Wed Dec 09, 2020 6:12 pm

Shannon Moore 2L wrote:Are seesaw and trigonal pyramidal the same shape? I am confused


Hi! No, seesaw and trigonal pyramidal are not the same shape. As aforementioned, seesaw has one lone pair and four bonding pairs while trigonal pyramidal has one lone pair and three bonding pairs. I have attached a picture of a table which I have found very helpful for memorizing molecular shape. Hope this helps!
Attachments
Screen Shot 2020-12-09 at 6.11.29 PM.png

Tobie Jessup 2E
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Re: Seesaw vs. trigonal pyramidal

Postby Tobie Jessup 2E » Thu Dec 10, 2020 7:32 pm

trigonal pyramidal is roughly the same bond angles as a tetrahedral, 109.5, but there is not a 4th peripheral atom in one spot. Seesaw is derived from he trigonal bipyramidal, where there is on lone pair in the plane with 2 other atoms.

Binyu You
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Re: Seesaw vs. trigonal pyramidal

Postby Binyu You » Sat Dec 12, 2020 9:45 am

I think seesaw is when 4 out of 5 are occupied, while trigonal pyramidial is when 3 out of 4 spots are occupied. Seesaw usually has bond wth 4 atoms and one pair of lone pair; trigonal pyramidal is when bonding wit 3 atoms and one pair of lone pair.

Kelly Tran 1J
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Re: Seesaw vs. trigonal pyramidal

Postby Kelly Tran 1J » Sat Dec 12, 2020 4:00 pm

Seesaw and trigonal pyramidal are not the same shape. Seesaw has 5 regions of electron density (1 of which is a lone pair while 4 are bonding pairs). Trigonal pyramidal has 4 regions of electron density (1 of which is a lone pair while 3 are bonding pairs).

Ethan Goode 2H
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Re: Seesaw vs. trigonal pyramidal

Postby Ethan Goode 2H » Sat Dec 12, 2020 4:01 pm

They are not the same shape. Both have one of their regions of electron densities as a lone pair, but seesaw has 5 regions while trigonal pyramidal has 4.

Mackenzie Stockton 2H
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Re: Seesaw vs. trigonal pyramidal

Postby Mackenzie Stockton 2H » Sat Dec 12, 2020 4:02 pm

See saw is AX4E , while trigonal pyramidal is AX3E

Mauricio Maravilla 3C
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Re: Seesaw vs. trigonal pyramidal

Postby Mauricio Maravilla 3C » Sat Dec 12, 2020 4:03 pm

Trigonal Pyramidal is the shape of a central atom that has 3 atoms bonded to it and one lone pair, while the seesaw shape forms when a molecule has one electron pair with 4 atoms bonded to the central atom.

Catie Donohue 2K
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Re: Seesaw vs. trigonal pyramidal

Postby Catie Donohue 2K » Sat Dec 12, 2020 4:07 pm

Brandon Pham 1K wrote:What Ashley said was correct, and:
-See-saw has bond angles of <90 and <120
-Trigonal pyramidal has bond angles of <107.5

Hi! Could you tell me how you figured out how bond angles were 107.5 - I thought it would be < 109.5 since there's a tetrahedral electron arrangement.

LovepreetSran_3H
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Re: Seesaw vs. trigonal pyramidal

Postby LovepreetSran_3H » Sat Dec 12, 2020 4:25 pm

Seesaw has 5 regions of electron density whereas trigonal planar has 4 regions of electron density.

Brandon Pham 1H
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Re: Seesaw vs. trigonal pyramidal

Postby Brandon Pham 1H » Sat Dec 12, 2020 8:05 pm

Catie Donohue 3I wrote:
Brandon Pham 1K wrote:What Ashley said was correct, and:
-See-saw has bond angles of <90 and <120
-Trigonal pyramidal has bond angles of <107.5

Hi! Could you tell me how you figured out how bond angles were 107.5 - I thought it would be < 109.5 since there's a tetrahedral electron arrangement.


Oh sorry. I believe both are correct. For the test, I think he'd use <109.5, sorry for the discrepancy.

Nan_Guan_1L
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Re: Seesaw vs. trigonal pyramidal

Postby Nan_Guan_1L » Sat Dec 12, 2020 11:55 pm

seesaw has 1 lone pair and 4 bonding pairs, that's a total of 5 areas of electron density.
trigonal pyramidal has 1 lone pair and 3 bonding pairs, that's a total of 6 electron density. hope that helps!

Simran Bains 2C
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Re: Seesaw vs. trigonal pyramidal

Postby Simran Bains 2C » Sun Dec 13, 2020 2:50 am

Seesaw its a trigonal by pyramidal shape with one lone pair, while trigonal pyramidal is a tetrahedral with one lone pair.

Talia Dini - 3I
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Re: Seesaw vs. trigonal pyramidal

Postby Talia Dini - 3I » Thu Dec 17, 2020 1:35 am

No, seesaw and trigonal pyramidal are not the same shape. Seesaw has 4 bonding pairs and 1 lone pair while trigonal pyramidal has 3 bonding pairs and 1 lone pair.

Jonathan Banh 1G
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Re: Seesaw vs. trigonal pyramidal

Postby Jonathan Banh 1G » Thu Dec 17, 2020 1:53 am

No, in regards to molecular shape, see-saw and trigonal pyramidal are not the same thing. The main difference between them is that they have different amounts of regions of electron density where a see-saw molecule has 5 while a trigonal pyramidal molecule has 4, which corresponds to a steric number of 5 and 4, respectively. Although both of them have only one lone pair, the difference in the amount of atoms results in different molecular shapes. Also note that because of the lone pair in both shapes, the bond angles will be less than their typical values. To be more specific, the bond angles in a trigonal pyramidal would be less than 109.5 degrees. On the other hand, those in a see-saw would be less than 90 and 120 degrees.

Susan Chamling 1F
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Re: Seesaw vs. trigonal pyramidal

Postby Susan Chamling 1F » Thu Dec 17, 2020 2:04 am

Hi! They aren’t the same shape; seesaw has 5 regions of electron density, one of which is a lone pair (AX4E), whole trigonal pyramidal has 4 regions of electron density, one of which is a lone pair (AX3E).

Adam_ElSayed_3B
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Joined: Wed Sep 30, 2020 9:48 pm

Re: Seesaw vs. trigonal pyramidal

Postby Adam_ElSayed_3B » Thu Dec 17, 2020 2:20 am

They aren't the same! One refers to a # of 5, the other to a 4. Others have explained shape!

America Ramirez 3H
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Re: Seesaw vs. trigonal pyramidal

Postby America Ramirez 3H » Thu Dec 17, 2020 9:05 am

They are two different shapes because the seesaw has 5 regions of electron density, trigonal pyramidal only has 4 regions of electron density.

Nicole Bruno Dis 1B
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Joined: Wed Sep 30, 2020 9:36 pm

Re: Seesaw vs. trigonal pyramidal

Postby Nicole Bruno Dis 1B » Thu Dec 17, 2020 9:24 am

No, seesaw and trigonal pyramidal are not the same. The seesaw shape has a lone pair in the equatorial position whilst the trigonal pyramidal shape does not have a lone pair.


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