1. The problem statement, all variables and given/known data Do alkenes only form carbocations while carbonyl groups only form carbanions? 2. Relevant equations NA 3. The attempt at a solution I understand the relative reactivity of carbocations and carbanions. How does one know when an organic compound follows heterolytic cleavage or homolytic cleavage of H? For example, do alkenes only make carbocations while ketones and aldehydes create carbanions?