广西高二英语《unit13 the properties of waterreading》课件 新人教版

1 Why is it blue? Water Planet What can water be used for? drink Wash clothes 3 irrigation transport 4 provide living space for marine life 5 They are floating on the surface of Dead Sea. Can you explain how they can do this? entertainment 6 Can you give me some words , phrases or sentences relative to water? 7 Where there is a river, there is a city! Where there is water, Where there is water, there is life!there is life! 2222 ndnd , March, March 9 What properties or characteristics What properties or characteristics do you know about water?do you know about water? colorless tasteless having no fixed shape three forms feeling wet keeping level absorbing heat propertiesproperties 10 11 Properties of Water Para.1 chemical structure Para.2 salinity Para.3 Density Para.4 Heat Capacity Para.5 Ocean motion Para.6 How is the text organized ? importance of Water Para.7 12 Fast Reading : 1. Water has a relatively low freezing point. 2. You will drown in the Dead Sea. 3. Water is liquid at room temperature. 4. Salt water is heavier than fresh water. 5. The density of water is 1,000kg/m3. 6. The ocean will freeze totally. 7. The salinity of the earths oceans is about 3.5% 8.When water freezes, its density increases. 13 True or False 1. There are about five billion species in the oceans ranging from the tiniest plankton to giants like sharks and whales. 2. The water molecule is made of two hydrogen atoms and one oxygen atom. F T 14 3. The reason why water can dissolve most substances on earth is that water has high heat capacity. 4. Water is a liquid at room temperature, and it has a relatively low freezing point. 5. The salinity of the earths oceans is about 35. F F T 15 6. Pure water has a higher freezing point and is lighter than salt water. 7. If a substance has a density 800kg/ m3, it will float on Water. 8. When water freezes, its density increases. T F T 16 9. Water gets smaller when it freezes. 10. Other recourses such as oil, gas, gold and so on, are as precious as a drop of rain. 11. The most important thing we can learn about water is that we must protect it and use it wisely. F F T 17 Introduction (Para1): Why do we call it an ocean planet? 18 19 Life on the earth began in the oceans Life on the earth began in the oceans about three billion years ago;about three billion years ago; 99% of the living space on earth is in 99% of the living space on earth is in the oceans; the oceans; There are about five million (known) There are about five million (known) species in the oceans;species in the oceans; Life in the oceans ranges from tiny Life in the oceans ranges from tiny plankton to giant sharks and whales .plankton to giant sharks and whales . Ocean is a great place to live. -Water. 20 What is water made up of ? The molecule of water is made up of two hydrogen atoms and one oxygen atom. 21 Salinity (Para3) sea water= salt water dissolved solids and gases pure water The salinity of the oceans:_. thirty-five parts per thousand (3.5%) Key points: (one kilogramme) (35 grammes) The salinity affects: _ and _. weightfreezing point (heavier)(lower) 22 Heat Capacity (Para5) Heat Capacity the amount of energy it takes to raise the temperature of a substance by one degree centigrade relatively high waterheat absorb and give off Create a stable environment so the ocean is a safe and comfortable habitat. 23 What do different densities in What do different densities in the ocean result in? the ocean result in? Water in the ocean is always moving.Water in the ocean is always moving.24 Waves 25 26 Density (Para4) Densitymassvolume Relationship Key points: The density of pure water:_. 1,000 kg/m3 (one cubic metre)(1,000 kilogrammes) Marine animals and plants take advantage of the density of