Atomic Electron Configurations

animation of electrons being 'placed' into an orbital The electron configuration is a listing of which atomic orbitals are occupied by electrons, and how many electrons are in each type of atomic orbital. The “ground state” electron configuration is the lowest energy combination of electrons in the atomic orbitals. Your task is to discover what the ground state electron configurations are – and how these can be predicted from the periodic table.

The Energy Ladder is a graphical representation of an atom's electron configuration in which the orbitals are arranged vertically in the order of their relative energy levels. Each box on the energy ladder represents an atomic orbital that can contain 0, 1, or 2 electrons.

Upon completion of this interactive learning object, students will be able to:

  • Arrange the electrons in an atom to obtain the correct electron configuration
  • Connect the correct electron configuration with the lowest energy for the atom
  • Predict the correct electron configuration from the atom's position on the periodic table

If you are using this learning object as part of a class your teacher may ask you to complete the companion Worksheet.

Teachers: Please review the Instructor's Guide for tips on implementing this simulation in the classroom.

Atomic Electron Configurations


angled wedge indicating that the listed elements increase in difficulty from left to right


Higher Energy

up arrow, indicates that energy levels go from low, as you begin at 1s, increasing as you move up the ladder towards 6p

Lower Energy


Shortcut Buttons


Jodye Selco

Jodye Selco is a Professor of Science Education (in the Center for Excellence in Mathematics and Science Teaching – CEMaST) and Chemistry at California State Polytechnic University Pomona. She is actively involved in research in physical chemistry as well as the teaching and learning of chemistry by all students. Professor Selco has been working with the teachers in Rialto USD for many years and has developed many learning experiences in science for teachers and students in the Rialto USD which have been adopted by many other teachers.

April Dawn

April Dawn is the Lead, Senior Instructional Designer for eLearning at California State Polytechnic University, Pomona. She provides instructional design consultation to assist faculty in redesigning existing courses and developing new courses for online, hybrid and face-to-face modes of instruction.

Richard Feldman

Richard Feldman is a multimedia developer for eLearning at California State Polytechnic University, Pomona. He creates interactive simulations that help faculty demonstrate concepts that are otherwise difficult to explain to students.

Other Credits: Unless otherwise specified, all images, graphics, and content in this simulation are property of California State Polytechnic University, Pomona.