1、Objectives Distinguish between elements单质单质 and compounds化合物化合物.Describe the organization of elements in the periodic table元素周期表元素周期表.Explain the laws of definite定比定律定比定律 and multiple proportions 倍比定律倍比定律element:单质单质,元素元素 Choose the mixture as homogeneous.a.brass(an alloy of zinc and copper)b.muddy
2、water c.blood d.powdered drink mix dissolved in waterExercises:Classification:solutionCan you see individual hydrogen and oxygen in the water?What is element and compound?UrBr2CuAn element is a pure substance that cannot be separated into simpler substances by physical or chemical means.单质单质Group di
3、scussion:Can you give some elements as many as you can?(In English)CuHgHe/consisting of a single type of atom Periodic TableWho was the first to invent the modern periodic table?based on the similarities and masses of the elementsperiod 周期group族族Compound 化合物化合物Whats the similarities between water an
4、d carbon dioxide CO2?Consist of two kinds of elementsPure substance,consist of oxygenmade up of two or more different elements that are combined chemicallyHow can you prove salt is made up of two elements?Can you taste 3 things?NaCl2How can you prove water is made up of two elements?The experiment?A
5、n 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 dioxi
6、de,oxygen,helium食盐食盐酒精酒精蔗糖蔗糖 Law of conservation of massMass is neither created nor destroyed during a chemical reactionit is conserved保存的质量守恒定律质量守恒定律Whats the change of iron?If the mass of reactants equal products?mass reactants =mass products A 13.0-g sample of X combines with a 34.0-g sample of Y
7、 to form the compound XY2.What is the mass of the reactants?Lets try:反应物生成物P 9:502.If 14.0g of N2 gas reacts with excess of hydrogen gas,Whats the mass of NH3 formed?History:Antoine Lavoisiermercury(II)oxideUse the data in the table to answer the following questions.选择选择=结果结果汇报结束汇报结束 谢谢观看谢谢观看！欢迎提出您的宝贵意见！欢迎提出您的宝贵意见！
