Seesaw vs. trigonal pyramidal

[Shannon Moore 2L]

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

[Ashley Ko 3I]

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

[IsaacLaw1E]

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]

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]

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]

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!

[Tobie Jessup 2E]

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]

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]

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]

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]

See saw is AX4E , while trigonal pyramidal is AX3E

[Mauricio Maravilla 3C]

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]

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]

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

[Brandon Pham 1H]

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]

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]

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

[Talia Dini - 3I]

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]

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]

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]

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

[America Ramirez 3H]

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]

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.