Reddit mentions of Molecular Quantum Mechanics

Haha.

But if you're serious, then you probably don't know many chemists. They know more about chemistry than your typical physicist, and you're asking a physical/inorganic chemistry question.

If you can find it in your library, check out Atkins' Molecular Quantum Mechanics book. It doesn't have electron affinity in it, but it's one of the best introductory texts out there.

Apart from that you can also work your way through textbooks, such as Molecular Quantum Mechanics, read popular publications such as A Brief history of time or The Elegant Universe (haven't read those unfortunately).

You can also visit the subreddit /r/Physics, to be up to date, ask questions and such, or even visit 4Chans /sci/ which gives you access to a large science and math guide.