Hey devendra , Chemistry is the science that deals with the properties, composition , and structure of substances (defined as elements and compounds), the transformations they undergo, and the energy that is released or absorbed during these processes. Every substance, whether naturally occurring or artificially produced, consists of one or more of the hundred-odd species of atoms that have been identified as elements. Although these atoms, in turn, are composed of more elementary particles, they are the basic building blocks of chemical substances; there is no quantity of oxygen , mercury , or gold , for example, smaller than an atom of that substance. Chemistry, therefore, is concerned not with the subatomic domain but with the properties of atoms and the laws governing their combinations and how the knowledge of these properties can be used to achieve specific purposes.

Chemical reactions occur when chemical bonds between atoms are formed or broken. The substances that go into a chemical reaction are called the reactants , and the substances produced at the end of the reaction are known as the products . An arrow is drawn between the reactants and products to indicate the direction of the chemical reaction, though a chemical reaction is not always a "one-way street".

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Dear candidate

Chemistry the branch of science which which is related to the substances of which matter is collected, and the study or analysis of their properties and chemical reactions which result in formation of new substances.

And a chemical reaction a process that involves rearrangement or combination of the molecular or ionic structure of a substance, which either result in change in physical form or nuclear reaction forming a new substance which means in a chemical reaction two substances are combined which are called as reactants after they are combined under particular conditions they form different substances like new compounds.

There are different types of chemical reactions like

• Combination
• Decomposition
• Displacement
• Double displacement
• Redox
• Synthesis
• Single replacement
• Double replacement

As a result we can say that chemistry is the study of substances that involve in chemical reactions and the process of chemical reactions and the study of the results of those chemical reactions

Hope this Information is helpful