Chemical physics is the study of chemical processes in terms of the atoms and particles that make up a system. Understanding chemistry at a smaller scale requires theories from many areas of physics, from thermodynamics to quantum mechanics.
A chemical reaction is a process during which one set of chemical substances is transformed into a group of products. Chemical reactions are not just isolated to laboratories- many processes in everyday life rely on chemical reactions. In nature there are many chemical reactions happening every second, for instance our bodies use chemical reactions to turn food into energy. We have also learnt to use chemical synthesis to make products we need. The greater our understanding of the processes involved in chemical reactions the more we can take advantage of natural reactions and the further we can develop chemical synthesis.
In all chemical reactions, molecules collide, and the bonds between them change. Of all the molecules that collide, only some will have high enough energy to react, so the more collision that occur the higher the chance of reaction. For this reason a higher rate of collision leads to a faster rate of reaction. Rate of collisions between molecules can be affected by factors such as the temperature and pressure; this can be explained using thermodynamics and other laws of classical physics.
The energy required to fuel a reaction is known as the activation energy. In some cases achieving this energy can be difficult or expensive to achieve. The activation energy is determined by how strong the bonds between atoms are, the stronger the bonds the higher the energy required to break them.
Chemical bonds are the bonds between different atoms; they are formed due to attraction between the atoms involved. This attraction may be between electrons and the nuclei or due to dipole attraction. A full explanation of chemical bonds must include the role of the electron pair. This is where quantum mechanics steps in.
On washing powder you may have seen adverts saying ‘now only need to wash at thirty’. This is because the washing powder companies have successfully lowered the activation energy of the reactions which cause their powder to clean the dirt from your clothes. They have done this with molecules called enzymes. In a simplified view enzymes weaken the chemical bonds allowing them to be broken more easily. Enzymes are involved in a broad range of research involving not only chemical physics but also biophysics. They can be used not only to make energy savings, but also to make reactions possible that otherwise wouldn’t be. Due to the amount of processes that rely on chemical reactions they are extremely useful to us.
Chemical Physicists are involved in trying to work out the mechanisms involved in natural chemical reactions as well as helping to create better synthetic ones. They use principles and mathematics taken from Physics to do this.
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Thermodynamics is very successful at describing the way energy interacts with itself and matter - but every now and then a paradox will pop up, or someone will spot an event which no one has an explanation for yet.
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