Humber Admissions Practice Test

What is activation energy?

1. Energy released during a reaction

2. Energy required for bond formation

3. Energy needed to get a reaction started

4. Energy that prevents reactions

The correct answer is: Energy needed to get a reaction started

Activation energy is defined as the minimum amount of energy required to initiate a chemical reaction. This energy is necessary to overcome the energy barrier that prevents reactants from converting into products. During a reaction, molecules must collide with sufficient energy to break existing bonds and allow for the reconfiguration of atoms to form new bonds, leading to products. The option that states activation energy is the energy needed to get a reaction started effectively captures the essence of this concept. It underscores the requirement for energy input in order to initiate the process of transformation from reactants to products. The other choices do not accurately represent activation energy. The notion of energy being released during a reaction pertains to the energy changes that occur after the reaction has commenced, rather than the energy needed to start it. Similarly, energy required for bond formation relates to the energy changes involved in creating new bonds in products, which happens after the activation energy has been provided. Lastly, the concept of energy that prevents reactions does not align with activation energy, as activation energy is about providing the necessary energy to overcome the barriers rather than preventing reactions.