What are the factors that determine the structure of matter ?

How do we deduce the structure experimentally ?

What drives a chemical reaction forward and how fast would it proceed ?

Is there a connection between the properties of individual molecules
with the bulk properties that arise from their collective behaviour ?

These are some of the major questions that physical chemistry addresses. Physical chemistry is the study of phenomena in chemical systems, such as those exemplified above, in terms of physical concepts and laws. The study of quantum chemistry gives rise to the understanding of the structure and bonding of matter whether they are solids, liquids or gases. The structure of matter can be obtained through spectroscopy which explores how light interacts with matter. Thermodynamics gives us information on the energetics of chemical reactions whether the reaction can proceed in the forward or backwards direction. If the rate of reaction is required, the field of chemical kinetics and dynamics will help us understand the process in detail down to the atomic or molecular level. Finally through the study of statistical mechanics, we hope to establish how the combined properties possessed by individual atoms and molecules give rise to measurable properties such as temperature and pressure in the bulk state.