Chemistry

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Chemistry (from Egyptian kēme (chem), meaning "earth") is the science that studies matter at the atomic to macromolecular scale, the reactions, transformations and aggregations of matter, as well as the energy and entropy released or absorbed during these processes. In short, chemistry studies molecules, crystals, and metals and is concerned with the composition and statistical properties of such structures, as well as their transformations and interactions to become materials encountered in everyday life. According to modern chemistry, the physical properties of materials are generally determined by their structure at the molecular or atomic scale, which is itself defined by interatomic electromagnetic forces, and laws of quantum mechanics and thermodynamics from various fields of physics. Robert Boyle (1661), Antoine Lavoisier (1787), and John Dalton (1808) can be considered the three fathers of modern chemistry, while some consider the earlier chemist Geber (d. 815) to be the "father of chemistry".

Introduction

Chemistry is often called "the central science" because it connects the other natural sciences, such as astronomy, physics, material science, biology, and geology. These connections are formed through various sub-disciplines that utilize concepts from multiple scientific disciplines. For example, physical chemistry involves applying the principles of physics to materials at the atomic and molecular level. The precise nature of the theoretical connection that chemistry (along with the other so-called special sciences) has with physics is a matter of research in philosophy of science.

Chemistry pertains to the interactions of matter. These interactions may be between two material substances or between matter and energy, especially in conjunction with the First Law of Thermodynamics. Traditional chemistry involves interactions between substances in chemical reactions, where one or more substances become one or more other substances. Sometimes these reactions are driven by energetic (enthalpic) considerations, such as when two highly energetic substances such as elemental hydrogen and oxygen react to form the less energetic substance water. Chemists often use reaction equations to summarize a specific reaction. The chemical reaction between hydrogen and oxygen is shown in the following equation:

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