Since this is a schoolwork question, please tell us what you think the answers are and why. Thanks.Joe20 said:
Trick question.Joe20 said:
The electron domain geometry is the spatial arrangement of electron domains (regions of electron density) around a central atom. It is determined by counting the number of bonding pairs and lone pairs of electrons around the central atom. The VSEPR (Valence Shell Electron Pair Repulsion) theory is used to predict the electron domain geometry by minimizing the repulsion between these electron domains.
Electron domain geometry considers all regions of electron density (bonding pairs and lone pairs) around the central atom, while molecular geometry only considers the arrangement of atoms (bonding pairs) and ignores lone pairs. Therefore, molecular geometry is derived from electron domain geometry but can differ if lone pairs are present.
Lone pairs occupy more space than bonding pairs because they are localized closer to the nucleus of the central atom. This increased repulsion can cause the bonding pairs to be pushed closer together, altering the angles between them and thus changing the molecular geometry compared to the electron domain geometry.
The common types of electron domain geometries are linear (2 electron domains), trigonal planar (3 electron domains), tetrahedral (4 electron domains), trigonal bipyramidal (5 electron domains), and octahedral (6 electron domains). Each geometry corresponds to a specific arrangement that minimizes electron pair repulsion.
To predict the molecular geometry, first determine the electron domain geometry by counting the bonding pairs and lone pairs around the central atom. Then, use the VSEPR theory to determine the arrangement of these electron domains. Finally, adjust for the presence of lone pairs to get the molecular geometry, noting that lone pairs will alter the ideal bond angles and shape.