# Which of the following molecule and geometry combinations is incorrect?

##
#a)# #"CF"_4# , tetrahedral molecular geometry, tetrahedral electron geometry

#b)# #"BeBr"_2# , linear molecular geometry, linear electron geometry

#c)# #"PF"_3# , pyramidal molecular geometry, trigonal planar electron geometry

#d)# #"H"_2"O"# , bent molecular geometry, tetrahedral electron geometry

##### 1 Answer

It is **trigonal bipyramidal**, not "pyramidal" (which does not exist), for the molecular geometry.

It is **tetrahedral** for the electron geometry.

I assume you are comparing:

#"CF"_4# #"BeBr"_2# #"H"_2"O"# #"PF"_3#

and that these are neutral molecules, not ions.

**GEOMETRY OF**

Carbon has

Hence, **tetrahedral** *electron* geometry **and** *molecular* geometry.

**GEOMETRY OF**

Beryllium has only

Of those two electron groups in

Thus, it has a **linear** *electron* geometry **and** *molecular* geometry.

**GEOMETRY OF**

Oxygen has

So,

Hence, it has a **tetrahedral** *electron* geometry and a **bent** *molecular* geometry. This is correct.

**GEOMETRY OF**

Phosphorus has

So,

Hence, it has a **tetrahedral** *electron* geometry and a **trigonal pyramidal** *molecular* geometry.