Angstroms stick around in chemistry and biochemistry because they're approximately the length of a carbon-hydrogen bond (~1.09Å), and therefore easy to reason a

Angstroms stick around in chemistry and biochemistry because they're approximately the length of a carbon-hydrogen bond (~1.09Å), and therefore easy to reason about and talk about. Saying 1.09e-10 meters is fine, I guess, but it's a lot easier and more intuitive to think in terms of units of CH (plus 10%), especially when you're talking about more than one. Remembering that CH is about 1Å and CC is about 1.5Å is such a basic approximation that it's become universal.