This JAVA applet provides the components that are needed to construct the shapes of two-dimensional representations of the isodensity surfaces of molecular orbitals in simple molecules. These qualitative representations help us to visualize the regions in the molecule that are electron rich and poor and to understand both the structure and reactivity of the molecule. The representations of the isodensity surfaces of bonding molecular orbitals can be approximated by overlapping the two-dimensional isodensity surfaces of the orbitals that are linearly combining to form the molecular orbitals.

    When the button below is clicked, a second window appears. There is a tool bar with "Components," "Element," "Label," and "Quantum Number n" at the top of this window. When the button is click, a pop-up menu appears. The menu contains lines, electrons, and shapes of the isodensity surfaces of atomic and hybrid orbitals. Select an isodensity surface by clicking the appropriate symbol in the menu. Next, click the button and select the chemical symbol of the central atom. Place the cursor at the point in the window where you wish to draw the isodensity surface, click the left mouse button and move the mouse slightly up or down . If you wish to rotate the isodensity surface or a line in the plane of the page, continue to press the left mouse button and move the cursor horizontally. Pick from the "Component" menu the isodensity surface of the atomic orbital that linearly combines with an orbital on the central atom to form a bonding molecular orbital between the two atoms, and select the chemical symbol of the terminal atom from the "Element" menu. Place the isodensity surface in the window and then move it until it overlaps with the isodensity surface of the orbital on the central atom. A bonding molecular orbital results from the overlap of orbitals or lobes of orbitals with the same algebraic sign. Therefore, the overlapping isodensity surfaces of the linearly combining orbitals or lobes of orbitals should have the same color. Construct the isodensity surfaces of the other bond molecular orbitals in the molecule in similar manner. Use the labels provided in the "Label" pop-up menu to identify each isodensity surface. See Tutorial for Experiment: Orbital Representation for additional help.

    When the cursor is placed on top of an object, the object is "highlighted" - the color of the object changes to yellow. If the right mouse button is pressed, a menu that contains the items "move," "delete," "reverse," and "clear window" is displayed. The selection of the "move" item will allow you to move the object horizontally or vertically. To move an object, place the cursor on "move" in the menu and click the left mouse button. Move the cursor and object to the new position and again click the left mouse button. The "reverse" item is used when two objects overlap and you wish to move the object on the bottom to the top. If "delete" is clicked, the "highlighted" object is removed from the window. When "clear window" is selected, all objects in the window are deleted.

    Construct an orbital representation of each compound listed below. Please include a printed copy of the representation. To capture the Java Applet Window with your represention, press the "Print Screen" key on your keyboard (upper right). Open your favorite word processing program - WordPerfect, Word, WordPad - and "Paste" the captured window to the blank page. Finally, print the page.

1. O₂SCl₂
2. SO₂
3. PH₃
4. F₂CO
5. ClSSCl
6. SeF₄
7. IF₅
8. H₃COH

    If you have constructed the orbital representations of the eight molecules and prepared copies of these representations for submission, then you may check the Solutions to the Orbital Representation Exercises