# Essential Elements

38 39 orbItal StructurES the whirly world of the very small At the scale of fundamental particles like the electron, energy comes in little bits, or quanta, and things down here behave like both particles andor waves, depending on your perspective. If an atom is pumped up with energy, electrons whizzing around the nucleus excitedly make discrete quantum jumps into new orbitals that fit together like a buzzing ethereal flower. Mathematical wave functions can predict the probability of finding an electron in a specific place. Nine times out of ten the electron will be found within the density plot opposite left. Some of the time its possibly on the other side of the galaxy. Each orbital may be inhabited by two electrons, with opposite spins to each other. The sphere top right represents a 1s orbital and the twins may be anywhere, including in the nucleus. The next orbital set, the 2p, fills as shown below. Three double teardrop shapes reflect around a nuclear nodal plane where electrons hardly ever go. As further orbitals fill, new electrons are forced into more and more exotic dances lower opposite, and see page 58. Strangely, the wavy nature of electrons means that we cant know their position and speed at the same time. A small but measurable uncertainty creeps in. Just looking for something so tiny radically alters its behaviour.