An electron is not a particle or a wave a such, but actually a region of space surrounding a
nucleus which "has a property of 'electron-ness'". These regions of space are fixed positions around the nucleus called orbitals. There are several types of orbital, each with its own shape and corresponding bond-type. 'Electron-ness' is the quality which allows
electrons to exist in a state which is defined as electrons.
Circular logic? You bet!
The electron leapt up two
shells, and fell again, emitting beautiful red
flashes and flickers. If it had been a person, it would have
wept with joy at the sight. But it was just an electron.