This web page explains what atomic orbitals are in a way that makes it appropriate for pre-college introductory chemistry or physics courses. It goes into detail on s and p orbitals, including their shapes and energies, while devoting less discussion to d and f orbitals. The author uses an analogy comparing an atom to a multi-story house -- with the nucleus on the ground floor and then various rooms (orbitals) on the higher floors occupied by the electrons. A full page debunks the misconception that "orbitals" are like "orbits" (common among beginning students). Beyond this foundation, the tutorial explores how electrons fill orbitals (from low-to-high energy). It concludes with a set of questions, with answers provided, for self-gauging understanding.
This page is part of Chemguide, an informational website developed by a veteran high school teacher to promote deeper understanding of concepts in introductory and intermediate-level chemistry.
Aufbau Principle, Heisenberg Uncertainty Principle, Hund's Rule, chemistry tutorial, electron configuration, energy levels, hydrogen electron model, orbital model, p orbitals, probability density, s orbitals, tutorial
Metadata instance created
February 20, 2013
by Caroline Hall
9-12: 4D/H1. Atoms are made of a positively charged nucleus surrounded by negatively charged electrons. The nucleus is a tiny fraction of the volume of an atom but makes up almost all of its mass. The nucleus is composed of protons and neutrons which have roughly the same mass but differ in that protons are positively charged while neutrons have no electric charge.
9-12: 4D/H2. The number of protons in the nucleus determines what an atom's electron configuration can be and so defines the element. An atom's electron configuration, particularly the outermost electrons, determines how the atom can interact with other atoms. Atoms form bonds to other atoms by transferring or sharing electrons.
4E. Energy Transformations
9-12: 4E/H5. When energy of an isolated atom or molecule changes, it does so in a definite jump from one value to another, with no possible values in between. The change in energy occurs when light is absorbed or emitted, so the light also has distinct energy values. The light emitted or absorbed by separate atoms or molecules (as in a gas) can be used to identify what the substance is.
4G. Forces of Nature
9-12: 4G/H8. The motion of electrons is far more affected by electrical forces than protons are because electrons are much less massive and are outside of the nucleus.
10. Historical Perspectives
10F. Understanding Fire
9-12: 10F/H5. Since Lavoisier and Dalton, the system for describing chemical reactions has been vastly extended to account for the configuration taken by atoms when they bond to one another and to describe the inner workings of atoms that account for why they bond as they do.
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This interactive model allows students to build virtual atoms and ions by adding/removing protons, electrons, and neutrons. As changes are made, the model displays atomic number, net charge, and isotope symbol.