Space-filling molecular models: Halogen expansion set

cults3d

The halogens are a compelling reason for employing space-filling models. With ball-and-stick models and especially rendering structures on paper, you can quickly convince yourself that all the atoms are roughly the same size. However, with most of the halogens, this observation decidedly doesn't hold true. Most of them are significantly larger than carbon or nitrogen. Although they are located further down the periodic table, so it would be expected for them to be larger, it's still surprising just how much bigger they are. "Are they really that irregularly shaped?" I hear you ask. Probably not; we don't know exactly what their shapes look like. They are likely more spherical in shape, but they can crowd nearby atoms, so some adjustments are made. "I thought one of the main points of space-filling models was to determine when things get too close together." That's true, but they don't overcrowd other atoms as much, and atomic orbitals appear to be more flexible than ABS (it would be interesting to try using flexible filament). Bromine is traditionally brown, but I didn't have any brown filament available (and I think I prefer it in gold).