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Chemistry is the science which deals with materials, their properties and the transformations they undergo. So chemistry is the study of the composition and properties of matter, their changes, the conditions under which such changes take place, and the energy changes which accompany them.

Chemistry is concerned with the nature of fire and the structure of water, it deals with colours, catalysis and crystal structure, with physical properties and chemical reactivity.

Chemistry is one of the fundamental sciences. It plays an important part in the development of biochemistry, physics, geo­logy and many other goes of science. Chemistry's origin goes back to ancient times, with the manufacture of bronze, iron, ceramica, glass.

Everyone now understands the importance of chemistry. The future of chemistry is practically unlimited. Rapid development of chemical industry will make it possible to create many new goods, machines, plastics, polymers, it will help to under­stand many new phenomena.

It is to be remembered that:

1. Chemistry is the study of substances, their structure, properties, and their reactions.

2. Matter exists as solids, liquids, or gases.

3. Homogeneous material is material with the same properties throughout.

4. Heterogeneous material is material consisting of parts with different properties.

5. Compound is a substance that can be decomposed into two or more substances.

6. Substance is a homogeneous species of matter with defi­nite chemical composition.

7. Chemical reactions are the processes that convert substances into other substances.

8. Alloy is a metallic material containing two or more ele­ments.

Common examples of substances are: water, sugar, salt, copper, iron and many others. Chemists study substances in order to learn as much as they can about their properties and about the reactions that change them into other substances. This knowledge is very important as it can make the world a better place to live in, it can make people happier, it can raise their standard of living.

Chemists discovered many laws, investigated many important phenomena in life. They produced many artificial substances which have valuable properties.

Chemistry has two main aspects: descriptive chemistry, the discovery of chemical facts, and theoretical chemistry the formulation of theories.

The broad field of chemistry may also be divided in other ways. An important division of chemistry is that into the branches of organic chemistry and inorganic chemistry.

Organic chemistry is the chemistry of the compounds of car­bon that occur in plants and animals.

Inorganic chemistry is the chemistry of the compounds of ele­ments other than carbon. Each of these branches of chemistry is in part descriptive and in part theoretical.

Analytical chemistry deals with the methods of separation. Synthetic chemistry deals with the methods by which complex bo­dies can be built from simpler substances. Physical chemistry deals with changes of state and with the motions of molecules. But at present time the scientists don't maintain this defini­tion.


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