What do wedges and dashes mean

Below are two drawings of a 4-carbon molecule with two chlorines and two bromines attached. Both drawings look like they represent the same molecule; however, if we add dashes and wedged bonds we will see that two different molecules could be depicted:.

The two molecules above are different, prove this to yourself by building a model. An easier way to compare the two molecules is to rotate one of the bonds here, it is the bond on the right :. Notice how the molecule on the right has both bromines on the same side and chlorines on the same side, whereas the first molecule is different. Read about dashed-wedged Line structures, bottom of page, to understand what has been introduced above. You will learn more about the importance of atomic connectivity in molecules as you continue on to learn about stereochemistry.

The following are examples of each, and how they can be used together. Above are 4-carbon chains with attached OH groups or Cl and Br atoms. Remember that each line represents a bond and that the carbons and hydrogens have been omitted.

When you look at or draw these structures, the straight lines illustrate atoms and bonds that are in the same plane, the plane of the paper in this case, computer screen. Measure content performance. Develop and improve products. List of Partners vendors. Share Flipboard Email. Anne Marie Helmenstine, Ph. Chemistry Expert. Helmenstine holds a Ph. She has taught science courses at the high school, college, and graduate levels. Facebook Facebook Twitter Twitter.

Updated November 14, Featured Video. Cite this Article Format. Helmenstine, Anne Marie, Ph. Coordination Number Definition in Chemistry. Math Glossary: Mathematics Terms and Definitions.

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