Cambridge IGCSE Chemistry · Syllabus 0620 · Atoms, Elements and Compounds
Cation
What is Cation?
A positively charged ion, formed when an atom loses one or more electrons. Metal atoms commonly form cations by losing their outer-shell electrons. The nucleus is unchanged, so the proton number and therefore the element stay the same; the positive charge arises simply because there are now more protons than electrons.
This definition is part of the Atoms, Elements and Compounds chapter in Cambridge IGCSE Chemistry.