🤓 Based on our data, we think this question is relevant for Professor Dornshuld's class at MSSTATE.
We have to notice that although the formula is the same (AF4), it has multiple possible shapes. The only way that this could happen is if the central atoms have different numbers of lone pairs.
Since we are treating lone pairs and surrounding atoms as different groups we are actually talking about Molecular Geometry.
The figure that follows contains ball-and-stick drawings of three possible shapes of an AF4 molecule.
Name an element A that is expected to lead to the AF4 structure shown in (i).