The energy released during a thunderstorm turns lightning into sources of activation energy.
Activation energy is a concept present in the field of chemical kinetics and other scientific specialties that refers to the minimum amount of energy required to start a process, phenomenon or activity.
It is essential that the molecules of a system have a basic level of energy so that a chemical reaction can occur, develop and be completed. Heat is usually the main source of activation energy , although it is not the only one (in a photochemical reaction , for example, the supplier of activation energy is light ). In this context, the reactant molecules manage to absorb thermal energy from their environment, which drives the acceleration of molecular movements and adds power and frequency to collisions, as well as causing atoms to shake.
It is important to know, on the one hand, that a chemical reaction is only completed when the molecules reach the peak of the activation barrier . The higher the energy barrier , say experts in the field, the lower the number of molecules with enough energy to overcome this obstacle. Therefore, it is also necessary to take into account that in chemical reactions there is a close link between the activation energy and the so-called reaction rate : the higher the activation energy , the slower the thermodynamic process . It is also worth mentioning that through catalysis it is possible, by means of a catalyst , to reduce the activation energy in order to increase the rate of a chemical reaction .
Types of activation energy
When searching for information related to the existing types of activation energy , the focus of interest is oriented, for example, to categories that are linked to the heat energy that, when sufficient to trigger a combustion , constitutes an activation energy . The minimum initial energy input for an exothermic chemical reaction to occur (such as the process of a combustion ) gives rise to several classifications.
Ignition sources can be caused by heat released by a mechanical phenomenon or process ( friction or compression ), chemical ( autoignition / spontaneous combustion ), electrical ( electrical sparks , for example) or nuclear (such as nuclear fusion ).
As can be seen when consulting the theory, there are generally two major sources of the activation energy that leads the reactants to become products: one is nature (the energy released by lightning during a storm reaches activation energy , to describe a specific case) and the other is the activity or effort of human beings to generate it.
In order to be triggered, a chemical reaction requires a minimum amount of energy, known as activation energy.
Importance
Activation energy is extremely necessary and important. Without it, a chemical reaction cannot begin.
It is constructive to keep in mind that, despite being linked to each other, the notions of activation energy and activation enthalpy are not synonyms. The latter is related to the energy needed to start the reaction . Specialists have established that the activation energy , vital for the reorganization of bonds, is determined by the change in enthalpy that is evident during the phase of passage of reagents to the so-called activated complex . The so-called activation entropy , on the other hand, marks the level of disorder or the degree of redistribution of energy in order to make the reaction possible.
For calculations involving activation energy , the Arrhenius equation is particularly useful. It is used to check the dependence of the rate constant , temperature and activation energy . It is worth noting that, in one way or another, the idea of activation energy gains presence or notoriety in, for example, collision theory and transition state theory .
Heat, a spark or a flame, provides the activation energy that allows combustion to develop, a process that also requires the use of fuel.
Examples of activation energy
Examples can help to make it easier to understand what activation energy is and how it works. Specifically, by analyzing the combustion process, it becomes clear that activation energy arises from a spark or flame coming into contact with a fuel .
Due to its characteristics and effects, lightning (i.e. a naturally occurring electrostatic discharge) arising in the context of a strong storm can also be a source of activation energy .
In order to achieve a sufficient level of energy to reach the transition state , on the other hand, catalysts are used, classified as heterogeneous or homogeneous depending on the existence, or not, of a catalyst that coincides with the substrate in a phase. With them, as deduced from practice and scientific experiments, it is feasible to increase the reaction speed or make a certain reaction develop at a lower temperature than the initial one. The case of inhibitors is different, since they have the capacity to deactivate a catalysis .