11.1.2—A simple model for the nuclear atom to include protons, neutrons and orbital
- Syllabus
- 9702–2028–2029
- Objective
- 11.1.2
- Level
- AS
The nuclear atom contains protons and neutrons in a small nucleus with electrons outside it
A simple nuclear model places positively charged protons and neutral neutrons in a tiny nucleus, with negatively charged electrons occupying the surrounding region.
Mass is concentrated mainly in nucleons while atomic size is set by the electron region. This is a model, not a literal set of classical orbits.
Changing the number of electrons can make an ion without changing the nucleus or the element identity.
Electrons are not inside the nucleus in this model, and a neutral atom does not mean it contains no charged particles.
ConceptA-Level CAIE Physics AS