Final answer:
The change in bond angles in molecular geometry depends on the arrangement of electron pairs according to VSEPR theory and cannot be determined without specific context. Therefore, without additional information about the molecular changes, the bond angle cannot be determined. The correct option is 4.
Step-by-step explanation:
When considering molecular geometry and the effects on bond angles, it's important to understand VSEPR theory (Valence Shell Electron Pair Repulsion theory). This theory states that electron pairs around a central atom tend to repel each other and therefore arrange themselves as far apart as possible to minimize repulsion.
As a result, as the number of bonding pairs or lone pairs on the central atom increases, the bond angles can either increase, decrease, or remain the same, depending on the specific arrangement of electrons.
For example, in a linear molecule like carbon dioxide (CO2), the bond angle is 180°. In a tetrahedral molecule like methane (CH4), the bond angles are 109.5°. When there are lone pairs, such as in the bent structure of water (H2O), the bond angle decreases to 104.5°, because lone pairs occupy more space than bonding pairs, pushing the bonded pairs closer together.
Thus, the bond angle could increase, decrease, or remain the same depending on the molecular geometry and the presence of bonding or lone electron pairs.
In the context of the original question, if 'the bond angle of molecular geometry increases' without additional context, option 4) 'The bond angle cannot be determined' is the most accurate answer because the change in bond angle depends on specfic molecular changes which are not provided.