Orbitals and Orbits

As a planet moves around its sun, a definite path can be plotted for it called an orbit. The familiar 20th century atomic model originally postulated by Neils Bohr in 1913 looks similar and features the electron orbiting around the nucleus as in the Hydrogen image below.



Bohr's Atomic Model of Hydrogen

The actuality is somewhat different, as electrons inhabit regions of space known as orbitals. An atomic orbital is essentially an electron "cloud" describing the probability of the position of the electrons. Therefore, an electron can be found within the range of an atomic orbital's shape at any point in time. This however, does not determine the exact position of the electron because it is constantly moving. However, if an electron is in a particular orbital it will have a particular definable energy.



Atomic Orbital (1s) of Hydrogen

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The Heisenberg Uncertainty Principle states that certain specific pairs of variables cannot be measured simultaneously with high accuracy. Most importantly, it states that within an atom, it is possible to measure the position, or the momentum, of a subatomic particle such as an electron. However, it is not possible to measure both of them at the same time, because the measuring process interferes to a substantial degree with what is being measured.

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The images presented on the following pages endeavour to visualise in graphic form the arrangements of the principle s, p & d atomic orbitals. For purposes of clarity the electron cloud mentioned above is encapsulated in a transparent bubble and an xyz plane has been included. Click on the icons below to view the s, p & d atomic orbitals respectively, or click on the text link to view all.