Hanna Björk wrote:
I am sure ki/qi is many different things for different people. Personally, I got comfortable with the concept when I started viewing it as a model for something, like Bohr's model of the atoms with the electrons in rounds circles around it. Completely wrong, as we know today, but still helpful for understanding how things work. I had a chemistry teacher who tried to skip the Bohr model and jump straight into sp3-hybridisation. It was terribly confusing, the class did not understand anything...
Yeah, that's pretty much my feeling. It's a model that's comparatively easy to usefully apply to certain situations and therefore is useful in those situations.
Although it's significant that sp3-hybridisation is also (part of) a model, though - it's just a model that's more consistent with reality in a broader range of cases...