There is no orbit of an electron around the nucleus. It is important to realize that electrons are quantum entities and they are not particles in the usual sense; electrons are singularities with zero size when traveling alone through free space, but when they are surrounding an atomic nucleus, they form "standing waves" that vibrate with the atomic nucleus at the center. These standing waves are called "orbitals", although they are not orbits in the strictest sense.
If this all sounds hard to understand, it is. Famous Nobel Physicist Richard Feynman, PhD, said, "If you think you understand Quantum Physics, then you don't understand Quantum Physics." This is because Quantum Physics is just too weird for our overgrown chimpanzee brains to ever fully understand.