Choose the compounds from following
substances (
)
食盐
酒精
蔗糖
table salt, water, alcohol, sucrose,
sulfuric acid, baking soda，
carbon dioxide, oxygen, helium
Law of conservation of mass
An electric current breaks down water into its components, oxygen and hydrogen.
Summarize:
Classify the following matters into （mixture、pure substance、element、 compound）：
g r o族 u p
period 周期
based on the similarities and masses of the elements
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
P 9: 50
2. If 14.0g of N2 gas reacts with excess of hydrogen gas, What’s the mass of NH3 formed?
History:
Antoine Lavoisier mercury (II) oxide
Use the data in the table to answer the following questions.
选择=结果
汇报结束 谢谢观看！ 欢迎提出您的宝贵意见！
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?
质量守恒定律
Mass is neither created nor destroyed during a chemical reaction—it is conserved保存的
What’s the change of iron? If the mass of reactants equal products?
mass reactants = mass products
反应物
生成物
Let’s try:
A 13.0-g sample of X combines with a 34.0-g sample of Y to form the compound XY2. What is the mass of the reactants?
element: 单质, 元素
Байду номын сангаас
Exercises:
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
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
Classification: solution
Can you see individual hydrogen and oxygen in the water?
What is element and compound?
Ur Br2
Cu
单质
An element is a pure substance that cannot be separated into simpler substances by physical or chemical means.
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?
electrolysis 电解