difference

[asalest 2K]

how can we tell the difference between trigonal planar and t-shaped?

[Valerie Doan 3I]

Trigonal planar molecules have 4 electron pairs, 1 lone PR and 3 bonding pairs (with 3 atoms). T-shaped molecules have 5 electron pairs, 2 lone pairs and 3 bonding pairs (with 3 atoms). Both of these have 3 bonding pairs with 3 separate atoms, but the amount of lone pairs differs.

[Lung Sheng Liang 3J]

Trigonal planar does not have a lone pair while t-shaped has 2 lone pairs.

[Gillian Gabrielsen2F]

Trigonal Planar has uniform bond angles of 120°. It has three regions of electron density: three bound atoms and no lone pairs.

T-shaped looks like a T; it doesn't have uniform bond angles, they're 90°, 180°. It has five regions of electron density: three bound atoms and two lone pairs.

(tshape, but with the lone pairs drawn as the yellow portions)

[David Liu 1E]

they have different amounts of electron dense areas - trigonal planar has 3 electron dense (paired) areas while t-shaped has 5 electron dense areas while 2 are lone pairs (aka there should be a different amount of electrons on the molecule that will help you tell)