This question is probably pretty silly looking at the complicated discussions going on here, but I'll ask none the less. Why don't Atoms spontaneously collapse? If there is a proton and there is an electron, shouldn't they attract each other and form a neutron? In trying to understand why this happens I was told that it's because of the quantization of energy. For the electron to move in towards the proton it would have to travel in such a way that it would violate the quantization, and have less than a quanta of energy. However, I later learned about Electron Capture, which clearly states that it is able to collapse. So my question is why doesn't it USUALLY collapse, and why does it collapse under certain circumstances? What keeps protons and electrons seperate 90% of the time, and allows them to unite at other points in their lives? Thanks, and try to use small words and talk slowly when answering. -- Physics n00b.