(b) When applying the VSEPR model, we count a double or triple bond as a single electron domain. Why is this justified?

Verified step by step guidance

1. Step 1: Understand the VSEPR model, which stands for Valence Shell Electron Pair Repulsion theory. It is used to predict the geometry of molecules based on the repulsion between electron pairs in the valence shell of the central atom.
2. Step 2: Recognize that in the VSEPR model, electron domains are regions where electrons are likely to be found. These include lone pairs, single bonds, double bonds, and triple bonds.
3. Step 3: Note that a double or triple bond is considered a single electron domain because the electrons in these bonds are shared between the same two atoms, and thus, they occupy the same region of space.
4. Step 4: Consider that the VSEPR model focuses on the spatial arrangement of electron domains around the central atom, and since double and triple bonds do not create additional regions of electron density, they are counted as one domain.
5. Step 5: Understand that this simplification helps in predicting the molecular geometry more easily, as it reduces the complexity of counting multiple electron pairs within the same bond.