Cambridge IGCSE Chemistry · Syllabus 0620 · The Periodic Table
Electronic Configuration
What is Electronic Configuration?
The arrangement of an atom's electrons in its shells, written as a list such as 2,8,1. The number of entries is the number of occupied shells and gives the period; the last entry is the number of outer-shell electrons and, for a main-group element, gives the group.
This definition is part of the The Periodic Table chapter in Cambridge IGCSE Chemistry.