Please contact the developer of this form processor to improve this message. Here, pay attention to the wedges and dashes. A specific example is shown in the figure below. And if you look closely, you’ll see that in each of these cases, we’re adding hydrogen (H) to carbon #1 of the double bond – i.e. Create. However, as we’ll see later, they do not always proceed through the same mechanism. Hydrogenation involves adding hydrogen $$(\text{H}_{2})$$ to an alkene. Notify me via e-mail if anyone answers my comment.