The exercise described below is an investigation into the types of chemical bonds that can form between two atoms. The graphical displays of the Bond Explorer software will help you construct an understanding of the behavior of electrons in different types of chemical bonds and the factors that determine the type of bond that will form between two atoms.

In this activity, you can use the Bond Explorer to investigate how the electronic structure of individual atomic orbitals determines the type of bond formed between two quasiatoms. (If you are unfamiliar with using the Bond Explorer, see the Introduction to the Bond Explorer, which appears when the Bond Explorer is launched on the Web.)

1. Part I.
   1. The screen opens with atomic orbitals set with the values of ground state hydrogen electrons (-13.6 eV). Click on the bonding molecular orbital and note the shape of the electron cloud. Then click on the antibonding orbital and note the shape of its electron cloud.
   2. Click on the atomic orbital on the left and increase or decrease its energy value. Move the atomic orbital on the right so that it has the same energy value. Examine both the bonding and antibonding orbitals formed from the overlap of the new atomic orbitals.
   3. Use the Edit menu to change both atomic orbitals 2pz. Examine the resulting bonding and antibonding orbitals and note their shapes and orientations.
   4. Repeat step 3 for other atomic orbitals, keeping the orbital and its energy the same for the two atomic orbitals.
   
   
2. Part II. Molecular Bonds Formed by Unequal Energy Atomic Orbitals
   1. Use the Edit menu to change both atomic orbitals to 1s. Then move the atomic orbital on the right so that it has a lower value than the atomic orbital on the left. Examine the resulting bonding and antibonding orbitals and note the shape and location of the electron clouds.
   2. Click on the bonding orbital. Then further separate the energy values of the atomic orbitals by increasing the orbital on the left and decreasing the orbital on the right. Observe changes in the shape and location of the electron cloud for the bonding orbital.
   3. Use the Edit menu to change orbitals 1 and 2 to 2pz. Examine the effect on the resulting bonding and antibonding orbitals as the difference in energy values of the two orbitals increases.

1. Between two similar atomic orbitals with the same energy
   1. Describe the bonding molecular orbital.
   2. Describe the antibonding molecular orbital.
2. Between two similar atomic orbitals with different energies
   1. Describe the bonding molecular orbital.
   2. Describe the antibonding molecular orbital.
3. Compare the symmetry of molecular orbitals as a function of atomic orbital energy
4. Compare the polarity of bonds formed by atomic orbitals with the same energy to those formed by atomic orbitals with different energies.
5. Compare bonding orbitals and antibonding orbitals for bonds created from atomic orbitals with different energy values.
6. Write a rule to help you predict the shape of the molecular orbital based on the energies of the original atomic orbitals.