Reactivity 3. What are the mechanisms of chemical change? Jaa Reactivity 3.1 Proton transfer reactions Reactivity 3.2 Electron transfer reactions Reactivity 3.2 Electron transfer reactions (HL) Reactivity 3.3 Electron Sharing Reactions Reactivity 3.4 Electron-pair Sharing Reactions (HL) Reactivity 3.4 Electron-pair sharing reactions