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How is it possible for two atoms to be held together by a chemical bond? What is a chemical bond?
This exercise focuses on a very simple molecule: H2. Imagine two hydrogen atoms that are widely separated; the two atoms are initially so far apart that they do not interact with each other. Each hydrogen atom contains a single electron in the hydrogen 1s orbital.
What happens as the two atoms are brought close together?
The exercise below allows you to explore this process using an energy diagram, an electron density plot, and a virtual reality representation of the isosurface. One hydrogen atom is given the label "A" and the other "B". The controls allow you to specify the distance between the two nuclei (the isosurfaces are only available for a limited number of separation distances). An option is provided that plots small dots at the locations of the two nuclei, thereby allowing you to observe the positions of the two nuclei.
Start with the atoms at a separation of 4 angstroms (r = 4 angstroms) and gradually bring the atoms close together. At each distance, examine the electron density and isosurface plots. Identify the energy of the system on the energy plot. When the left mouse button is pressed while the cursor is over the energy plot, the position of the cursor on the plot is displayed.
There are three sets of interactions in this system:
Answers the following questions in terms of these interactions using your observations of the energy, electron density, and isosurface plots.
This material is based upon work supported by the National Science Foundation under Grant Number 1246120