general knowledge ofchemistry - 副本.ppt大学化学专业英语课件.pptVIP

Major branches of chemistry Analytical chemistry Physical chemistry Organic chemistry Inorganic chemistry Biochemistry Analytical chemistry The study of what types of elements and compounds are present in a sample of matter－called qualitative analysis－and how much of each element and compound is present in a sample of matter－called quantitative analysis. Physical chemistry The study of the scientific laws and theories that attempt to describe and explain the structure of matter, the chemical bonds that hold matter together, the changes that matter undergoes, and energy involved in these changes. Organic chemistry The study of the properties and reactions of hydrocarbons, compounds derived from hydrocarbons that contain one or more other elements such as oxygen, nitrogen, sulfur, phosphorus, and chlorine. Biochemistry The study of the properties and reactions of compounds found in living organisms and those that are important to living organisms. Inorganic, organic, analytical, physical chemistry, and biochemistry are the main branches of chemistry, but it is possible to combine portions of them, or to elaborate on them in many ways. The periodic table In 1869, Mendeleev (1834-1907) of Russia published periodic arrangements of the elements, which were arranged in order of increasing atomic weights. Vertical columns of elements are formed having identical or similar outer-shell electron structures and thus similar chemical properties. The number of group 1A－lithium, sodium, potassium, rubidium, cesium, and francium－are known as the alkali metals(j碱金属）. The members of group 7A－fluorine, chlorine, bromine, iodine, and astatine－are known as halogens.（卤素） The periodic table has been used for studying the relationships of many properties of the elements. Symbols for some of the elements Elements with symbols not based on their modern names Lesson 1 Elements and Compounds Q A Elements are pure substances that can not be decomposed into simpler substances by ordinary ch