Chemistry is the science that studies the structure, composition, and properties of substances. It also includes the study of how these substances undergo certain chemical changes and how they release or absorb energy in the process of transformation.

1. Physical Chemistry.
   Application of pure physics to chemical problems Physical chemistry involves the study of the behavior of substances at different scales, from the macroscopic to the subatomic level. Unlike other branches, it deals mainly with the laws of physics that underlie all chemical interactions.
2. organic chemistry
   This field of chemistry deals mainly with the study of the chemical composition, structure, and physical properties of organic compounds. It also involves evaluating the chemical reactivity of organic compounds to understand their behavior. Organic chemistry plays a critical role in the development of common household chemicals, foods, and fuels. Advances in this field have contributed greatly to our society, such as the synthesis of polymers (which include all plastics and rubber products), numerous drugs, and other useful compounds such as ethanol and insulin.
3. inorganic chemistry
   The purpose of this field is to study the structure, composition, and behavior of these compounds. Some common examples of inorganic compounds include silicon dioxide (used in solar cells and computer chips), sulfuric acid (used in fertilizers and household products), and sodium chloride (used as table salt). All can be classified as bases, acids, oxides, and salts.
4. Analytical Chemistry
   Analytical chemistry uses advanced methods and instruments to isolate specific compounds, identify those compounds, and quantify their content in a product. It can be divided into two areas: quantitative analysis and qualitative analysis. The first is used to determine the absolute value or relative amount of one or more substances present in a compound. The second is concerned with determining the quality of a particular compound, regardless of its concentration or quantity.
5. Nuclear Chemistry.
   Nuclear chemistry deals with the study of changes in the nuclei of elements that are the source of nuclear energy and radioactivity. Some elements on Earth are radioactive. They spontaneously emit radiation (such as alpha, beta, or gamma rays). Unlike ordinary chemical reactions, which form compounds, nuclear reactions turn one element into another. This property is used in nuclear power plants to collect and store nuclear energy.
6. Biochemistry
   Biochemistry studies the chemicals and processes that occur in animals, plants, and microorganisms and the changes they undergo during life. It is essentially a laboratory science that combines chemistry and biology. It focuses on what happens inside living cells and how they communicate with each other as they grow or fight disease. It primarily studies the structure, function, and interaction of biological macromolecules such as carbohydrates, lipids, nucleic acids, and proteins.
7. Computational Chemistry
   As the name implies, computational chemistry uses computer simulations to calculate the structures and properties of compounds or groups of molecules. Although it is not an exact description of real chemistry, chemical phenomena can be explained to some extent in approximate quantitative or qualitative computational schemes.
8. Quantum Chemistry.
   Simply put, quantum chemistry is the study of very small particles. This field emerged with the discovery of subatomic particles – electrons, protons, and neutrons. One of the main goals of quantum chemistry is to understand electronic structure and molecular dynamics using Schrödinger’s equations.
9. Astrochemistry
   Astrochemistry is the science that studies the chemical composition of matter in space and the processes that led to that composition. It applies to both the solar system and the interstellar medium. Astrochemists, who are part astronomers and part chemists, analyze molecules and ions in outer space to find out what role they play in the composition of the universe.
10. Phytochemistry
    Phytochemistry is the study of the chemical processes involved in plant life and the chemical compounds produced by plants. Its main purpose is to study phytochemicals, the biologically active plant nutrient chemicals in vegetables, grains, fruits, and other plant foods that can provide health benefits beyond the standard diet.
11. Green Chemistry.
    Minimizing the use and production of hazardous/unwanted chemicals and substances. Green chemistry is primarily concerned with optimizing and creating chemical processes and products that aim to reduce (or completely eliminate) toxic substances produced in the environment.