Introduction of chemistry

Chemistry is everywhere! We can find chemistry reactions in our life: in air, water, soil, and plants. The most important chemical reaction, for example, photosynthesis, the process via chlorophyll of plants, transferring the energy from sunlight to produce sugar:

                                 6H₂O + 6CO₂  ------> C₆H₁₂O₆+ 6O₂

All organic matter produced via photosynthesis eventually is then oxidized and converted back to carbon dioxide and water:

                                       C₆H₁₂O₆    +   6O₂  ------->  6CO₂  +  6H₂O

Another example, combustion of S-containing fuel in electric power plants, generating sulfur dioxide, which has great impact on human health:

                                 S (organic S + FeS₂ pyrite) + O₂ --> SO₂

and in gas-phase sulfur dioxide is converted into sulfuric acid, the major source of acid rain, which has great impact on our eco-environment:

                                  HOSO₂· + O₂       --> HO₂2+ M

                                   HOSO₂· + O₂      --> HO₂· + SO₃

                                     SO₃ + H₂O + M  -->  H₂SO₄ + M    

Chemistry is the science of materials. Any subject that deals with materials in our life is related with chemistry.  Chemistry, therefore, is a fundamental and practical science and is not difficult to learn. We can study the fundamental concepts yourself in an order, starting from introduction of chemistry, inorganic chemistry, analytical chemistry, organic chemistry, and physical chemistry. In addition, after we learn those essential concepts, we are able to understand many essential concepts of environmental chemistry, geochemistry and biochemistry, and chemistry reaction in our daily life!