Brief Instructions An electron configuration is a method of indicating the arrangement of electrons about a nucleus. A typical electron configuration consists of numbers, letters, and superscripts with the following format:

1. A number indicates the energy level (The number is called the principal quantum number.).

2. A letter indicates the type of sublevel/orbital; s, p, d, f.

3. A superscript indicates the number of electrons in the orbital. Example: ls2 means that there are two electrons in the ‘s’ orbital of the first energy level. The element is helium.