( ) Unit 13 Reading Talk about the earth and the importance of water for life. Animals and plants cannot live without water. 1.What is our earth made up of ? 2.What do you think of the role water plays in our daily life ? 3.Could you please give some examples ? Our earth is mostly made up of waters. tortoise water.wmv water.wmv What is water made up of ? The molecule of water is made up of two hydrogen atoms and one oxygen atom. What properties or characteristics do you know about water? colorless tasteless having no fixed shape three forms feeling wet keeping level ? absorbing heat propertiesproperties The paper wont fall off. Because the air pressure can hold the paper and the water wont flow out. The water and the oil wont mix. The oil floats on the water. It is because the densities of them are different. Water has larger density and mass. The chalk will dissolve in the water. It is because water has the ability to dissolve the soluble ( ) things and matters. The ice cube floats on both salt water and fresh water, but ice dissolves faster in salt water. Because ice has smaller density and it can float on the fresh water and salt can help dissolve. While-reading The properties of water Ocean Motion Heat Capacity Salinity Chemical Structure Density True or False 1. Water is a liquid at room temperature, and it has a relatively high freezing point. 2. The reason why water can dissolve most substances on earth is that water has high heat capacity. T F 3. Like all the other substances, water gets smaller when it freezes. 4. Pure water has a higher freezing point and lighter than salt water. 5. The salinity of the earths oceans is about 3.5%. 6. When water freezes, its density increases. F F F T 7. Other recourses such as oil, gas, gold etc is as precious as a drop of rain. 8. There are about five billion species in the oceans ranging from the tiniest plankton to giants like sharks and whales. T F 9. The water molecule is made of two hydrogen atoms and one oxygen atom. 10. Pure water has a higher freezing point and is lighter than salt water. 11. If a substance has a density 888kg/ m3, it will float on Water. F T T 12. The heat capacity is relatively high, so that most animals dont like living in it. 13. The most important thing we can learn about water, is that we must protect it and use it wisely. F T ( )1.Based on Para. I, the author tells us that there are various species in the oceans, indicating that ____. A. Water plays a great role for marine life. B. Ocean is a good place for life. C. There are many reasons for tiniest plankton and giants like sharks and whales D. Ocean is part of the earth ( )2.The water in the ocean is always moving in that _____. A. The temperature of sea water is relatively high. B. Waters density affect changes in salinity and temperature. C. Changes in salinity and temperature have effect on waters density. D. Waters in rivers always flow into the ocean. ( )3.Generally speaking,human beings are ______ to large or suddenly changes in temperature. A. generous B. objective C. subjective D. sensitive Reading Comprehension A C D Properties of Water Para.1 chemical structure Para.2 salinity Para.3 Density Para.4 Heat Capacity Para.5 Ocean motion Para.6 How the text is organized. chemical structure of water Para.2 water molecule two hydrogen atoms one oxygen atom The water molecule is made up of two hydrogen atoms and one oxygen atom. The chemical structure of water makes it an excellent medium for life and also makes it different from almost everything else on earth. Key points: salinity Para.3 sea water dissolved solid and gases pure water Key points: The salinity of the earths oceans is about thirty-five parts per thousand. There are about 35 grammes of dissolved solids and gases in one kilogramme of water. Sea water consists of dissolved solid and gases as well as pure water. = salt water Compared with pure water, Salt water has a low freezing point and is heavy. Density Para.4 massvolumeDensity key points : Density is the relationship between mass and volume, measured in kilogrammes per cubic metre. The density of pure water is 1,000 kg/m3. One cubic metre of water weighs one thousand kilogrammes. Heat Capacity Para.5 the amount of energy it takes to raise the temperature of a substance by one degree centigrade waterheat absorb and give off The ocean has a stable environment in that water can absorb and give off heat to keep both the temperatures of the ocean and the earth steady. relatively high Heat Capacity Ocean motion Para.6 water in the ocean always moving changes in salinity and temperature waters density affect It is very important to learn about the properties of water. We must protect water and use it wisely. Water is what makes life possible. Language points 1. range fromto: vary in a specified limits e.g. The temperatures here range from 10 to 30C. 10 30 2. all the way e.g. Mrs Wang came all the way here. 3. makes it an excellent medium make + n.+ n. e.g. I want to make my sister a pianist. 4. make it different from make it + adj. e.g. You must make it clear that why you are late for school. 5. is made up of e.g. The water molecule is made up of two hydrogen atoms and one oxygen atom. 6. break down: , e.g. Chemicals in the body break our food down into useful substances. 7. mix .with: mix joy with sorrow 8. affect: ; e.g. Smoking affects health. 9. freezing: adj. frozen: adj. a freezing glance be freezing cold 10. mass: quality ( ) the masses , e.g. The masses have boundless creative power. a mass of e.g. Before the rain, the sky was a mass of clouds. 11. is measured in measure v. e.g. Whether a girl is beautiful or not is measured by her soul. measure n. e.g. Kilogramme is the measure of weight. 12. absorb: take in e.g.. The ice absorbs heat and turns into water. absorb ones attention=draw ones attention 13. stable: balanced a stable relationship a stable man 14. sensitive: .. be sensitive to e.g. You should be sensitive to the change of the society. 15. steady: ; ; be steady in ones purpose e.g. If you are steady in your purpose, your dream will come true. make steady progress a steady man 16. addto: / add fuel to the flame add up to Homework 1. Finish exercises in the Practicing in the Workbook. 2. Preview the Integrating Skills.