Atomic number
The atomic number Z equals the number of protons and identifies an element. A neutral atom has the same number of electrons as protons.
Explore a simplified model of atomic structure. The nucleus contains protons and neutrons, while electrons are represented outside it. The drawing is schematic, not to physical scale.
The atomic number Z equals the number of protons and identifies an element. A neutral atom has the same number of electrons as protons.
Isotopes have the same number of protons but different numbers of neutrons. Ions form when atoms gain or lose electrons.
Select an element and compare its atomic number, particles, and shell information. Use the visualizer to connect numerical data with the structure.
Modern quantum mechanics describes electrons with orbitals and probability distributions; the shell-like picture is an introductory visualization.
What determines an element’s identity? What changes when an atom becomes an ion? What is different between isotopes?