OT: "Deep" question for chemistry or physics majors - long

[Filliam H. Muffman]

You might want to look at The Mechanical Universe series for a little more background in basic physics for that age. It covers emissions briefly.
http://en.wikipedia.org/wiki/The_Mechanical_Universe

Looks like TheTominator covered it pretty well. It is one of those topics that gets really complicated the more you dig into it.