Please forward this error screen to 216. In the scope chemistry the central science pdf free its subject, chemistry occupies an intermediate position between physics and biology.
The history of chemistry spans a period from very old times to the present. Since several millennia BC, civilizations were using technologies that would eventually form the basis of the various branches of chemistry. It was unsuccessful in explaining the nature of matter and its transformations, but, by performing experiments and recording the results, alchemists set the stage for modern chemistry. In origin, the term is borrowed from the Greek χημία or χημεία.
The basis of such a chemical transformation is the rearrangement of electrons in the chemical bonds between atoms. The number of atoms on the left and the right in the equation for a chemical transformation is equal. The type of chemical reactions a substance may undergo and the energy changes that may accompany it are constrained by certain basic rules, known as chemical laws. Most chemists specialize in one or more sub-disciplines. The atom is the basic unit of chemistry.