The visible lines in the spectrum of hydrogen. But nothing else. The problem is there's more going on in a multi-electron atom, and it's not just that more electrons are attracted to the same nucleus. Much harder to deal with. And now all freshman chemistry professors are stuck trying to get their students to believe that electron particles are really electron waves .
Nobody knows how it can be like that.
In essence, all matter gets where its wave can go but appears as a particle when it gets there. Worse still, it makes its own matter wave, like God surfing. Such small wavelengths don't diffract on anything, so none of us ever spontaneously breaks up into a rainbow. It presumes particle thinking. Since we can't have more angular nodes than there were nodes in the first place, l can never exceed n-1.