Hiya. I've gotten behind in physics lately. Disturbingly so, in fact. I just can't stand how little I know, so I've recently undertaken the task of educating myself using Wikipedia, but it's terribly hard. I may have misinterpreted some things, and some things don't make much sense at all, so I'll be posting here every now and then. Anyways, what I want to know, basically, is what attracts what in an atom, and what repels what. Here's what I understand so far: Electromagnetic force dictates that protons will repel each other, electrons will repel each other, and protons & electrons will be attracted to each other. Neutrons are electrically neutral. Protons are attracted to each other because of the strong (but short ranged) nuclear force that attracts quarks within protons. While protons would normally repel each other, if they manage to get close enough to each other strong nuclear force will overcome the electromagnetic force that normally repels them and they'll be bound. I'm assuming that neutrons are also bound by strong nuclear force, and this is what creates a nucleus. Electrons are bound to atoms by electromagnetic force. And now for some questions... Wikipedia is giving me the impression that atoms can be stuck with an extra electron. I would think this should be immediately flung out as radiation as the combined repulsion from the other electrons is stronger than the combined attraction from the protons. Is this true? Also, will an atom with a net charge of +1 transfer an electron to an atom with a net charge of -1? In what ways can neutrons affect an atom? They're electrically neutral, I would think they only add mass to the atom. And where exactly does weak nuclear force come in? Sorry if I'm being a "help vampire," but I'm a bit confused.