单质和化合物-Elements-and-Compounds.pptVIP

Elements and Compounds * * Objectives ? Distinguish between elements单质 and compounds化合物. ? Describe the organization of elements in the periodic table元素周期表. ? Explain the laws of definite定比定律 and multiple proportions 倍比定律 element: 单质, 元素 Choose the mixture as homogeneous. a. brass (an alloy of zinc and copper) b. muddy water c. blood d. powdered drink mix dissolved in water Exercises: Classification: solution Can you see individual hydrogen and oxygen in the water? What is element and compound? Ur Br2 Cu An element is a pure substance that cannot be separated into simpler substances by physical or chemical means. 单质 Group discussion: Can you give some elements as many as you can? (In English) Cu Hg He /consisting of a single type of?atom Periodic Table Who was the first to invent the modern periodic table? based on the similarities and masses of the elements period 周期 group 族 Compound 化合物 What’s the similarities between water and carbon dioxide CO2? Consist of two kinds of elements Pure substance, consist of oxygen made up of two or more different elements that are combined chemically How can you prove salt is made up of two elements? Can you taste 3 things? Na Cl2 How can you prove water is made up of two elements? The experiment? An electric current breaks down water into its components, oxygen and hydrogen. electrolysis 电解 Summarize: Classify the following matters into （mixture、pure substance、element、compound）： Choose the compounds from following substances ( ) table salt, water, alcohol, sucrose, sulfuric acid, baking soda， carbon dioxide, oxygen, helium 食盐 酒精 蔗糖 *