Electron

Electrons are negatively charged particles that orbit around a atom nucleus. The symbol is e− is normally used, but beta (greek letter) is used in nuclear physics and radiochemistry. 
Electrons are quantum particles. Picture watching fireflies. Each one blinks at random, but it is possible to see where they are abundant and where they are rare if you watch for a while. Electrons act like that. It's been said that quantum particles look like waves, but act like particles. They're will-o-the-wisps, maybe here, maybe there. But the likelihood of seeing one here and not seeing one there has a pattern which which is the wavelike nature of an electron. Turn the equation which describes probability as a function of radius into an algorithm. Use a random number generator to create an angle number. Plot the numbers on an (r,th) plane, run the routine a few thousand times. Speed up the display enough, and the electrons will flicker around making a 1s orbital.