What is the term for the region that surrounds the nucleus of an atom?

The term for the region that surrounds the nucleus of an atom is the electron shell. Electron shells are specific energy levels where electrons are likely to be found around the nucleus. Each shell can hold a certain number of electrons and is organized in layers based on their distance from the nucleus. The arrangement of these shells is fundamental to understanding an atom's structure and how it interacts with other atoms, as they determine the chemical properties of an element.

The term "nuclear zone" is not widely recognized in atomic theory, and it does not accurately define the area where electrons are distributed. "Orbital space" refers more specifically to the three-dimensional regions (orbitals) within each electron shell where electrons are likely to be located, but it is not used to describe the entire region encompassing all shells. "Atom cloud" may suggest the probabilistic distribution of electrons around the nucleus as described by quantum mechanics, but it lacks the precision of "electron shell" and does not denote the structured layers of electron arrangement.