In this case, two electrons from each atom are shared. This is called a double bond. Explain to students that the oxygen molecules that are present in our air are made up of 2 oxygen atoms. This ...

The rule says it is impossible for these compounds to have a double bond connected to the carbon at the junction between the rings because the bond would have to be twisted and bent far outside ...

According to Bredt, it is impossible for these molecules to have a carbon–carbon double bond on either of the "bridgehead" atoms where the two ring structures meet. Molecules with carbon ...