The harder you try to locate the electron, the less you know about its velocity. The harder you try to measure its velocity, the less you know about its location. According to current theories of quantum mechanics , there is no way around this. It is impossible to say where an electron in an atom is going. This is random motion.
Random motion is unpredictable according to current theory.
We now know that atoms move. For example, an atom in a gas is free to bounce around within its container. This motion appears random, but is completely predictable according to current theories of classical mechanics . In practice, however, there is no way to do this with any degree of accuracy for an extended period of time. Every measurement has error associated with it.