This isn't technically a homework problem; I'm reading about Sn2 reactions and the basicity of halogen ions came up and for some reason I can't get my head around this Chem I concept. Please point out the flaw in this thinking: 1) Fluorine (F) is a small, electronegative atom 2) F will hold onto it's electrons super tightly 3) Thus, it will less readily donate electrons. 4) Conclusion: F is a sucky Lewis base. --PROBLEM: F- is a stronger base than I-. I KNOW that I can think about F- vs I- in terms of conjugate acids, or in terms of Bronsted-Lowry bases. I just want to know what's wrong with this thinking in particular, and why this thought process is leading me to the wrong conclusion. Much thanks! And no, I don't know why I'm making this simple concept harder for myself. But I know that on the test this will be my first thought progression and I WILL mess up if I don't figure out what's wrong with it.