Do you know about orbitals?

What it is: A way of describing how electrons are distributed in space around an atom. It’s determined by quantum mechanics.
Why you should care: Orbitals help explain the shapes of molecules — for example why an H2O molecule makes a V. Of course, you can’t see a bunch of little “V”s with your eyes when you look at a glass of water, but various sophisticated techniques can tease out these shapes at the smallest scale.