I wanted to now what is the molecular geometry of SeBr4, because I believe is a trigonal bipyramid...but I am not sure...please help me....

I thought it was a see-saw shape. See

http://www.stolaf.edu/depts/chemistry/mo/struc/explore.htm

You can see SeF4, the shape of SeBr4 is similar, but the angles are 120/90 deg as I recall. Nearly same shape

I think both of you are correct. SF4 is AB4U (5 domains) and is trigonal bipyramidal for the electronic geometry and see-saw for molecular geometry. SeBr4 should be the same.

Well, it seems like we have a case of molecular geometry confusion! But fear not, my friend! Let me bring some clownish clarity to this chemical conundrum.

So, SeBr4 does indeed have a trigonal bipyramidal electronic geometry, just like SF4. However, when it comes to molecular geometry, it's more like a see-saw. A see-saw ride for those little chemical molecules, isn't that exciting?

Picture this: the central selenium atom is surrounded by four bromine atoms and one lone pair. It's like having four friends on a see-saw with an extra ghost friend sitting on the ground. On the molecular see-saw, the angles between the bromine atoms will be around 90 degrees, and the angle between the lone pair and the bromine atoms will be around 120 degrees. Quite the circus act, I must say!

So, in summary, the molecular geometry of SeBr4 is indeed a see-saw, just like SF4, but with slightly different angles. Now that we've sorted that out, let's move on to more molecular amusement, shall we?

Yes, you are correct in thinking that the molecular geometry of SeBr4 is see-saw shaped. The electronic geometry of SeBr4 is trigonal bipyramidal because it has five electron domains (one selenium atom and four bromine atoms). However, due to the presence of a lone pair of electrons on the central selenium atom, the molecular geometry is distorted, resulting in a see-saw shape. The angles in SeBr4 are indeed approximately 120 degrees and 90 degrees.

To determine the molecular geometry of SeBr4, we need to first determine its electron domain geometry.

The electron domain geometry is the arrangement of electron domains (bonding and non-bonding pairs) around the central atom. In the case of SeBr4, we have a central selenium atom (Se) and four bonded bromine atoms (Br).

To determine the electron domain geometry, we count the total number of electron domains. In this case, the central selenium atom has four bonded pairs of electrons, giving us a total of four electron domains.

Based on this, the electron domain geometry can be determined as trigonal bipyramidal. This means that we have three equatorial positions and two axial positions.

Next, we determine the molecular geometry, which describes the arrangement of atoms around the central atom, taking into account both the bonding and non-bonding electron pairs.

In the case of SeBr4, there are no lone pairs on the central selenium atom, as all four domains are bonding pairs. As a result, the molecular geometry is also trigonal bipyramidal, just like the electron domain geometry.

Therefore, you were correct in thinking that the molecular geometry of SeBr4 is trigonal bipyramidal.

The information provided in the link you shared is accurate, as it mentions that SeF4 has a see-saw molecular geometry. Since SeBr4 has a similar structure, it is reasonable to assume that its molecular geometry is also see-saw, with the angles being approximately 120° and 90°, as you recall.

In summary, the molecular geometry of SeBr4 is trigonal bipyramidal, similar to SeF4.