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Chemistry Reading Competition

Chemistry Reading Competition. 3B Group 9. Content. Introduction of the book Article 1 : Why doesn't the 3 Second Glue adhere to the tube? Article 2 : What are the differences among green tea, red tea and oolong tea ?.

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Chemistry Reading Competition

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  1. Chemistry Reading Competition 3B Group 9

  2. Content • Introduction of the book • Article 1 : Why doesn't the 3 Second Glue adhere to the tube? • Article 2 : What are the differences among green tea, red tea and oolong tea?

  3. Introduction of Book Title: 蘇老師生活化學快問妙答 (Dr. Joe & What You Didn't Know: 177 Fascinating Questions & Answers about the Chemistry of Everyday Life) Author: 蘇瓦茲 Schwarcz, Joe

  4. Why did we find it interesting • Dr. Joe used simply scientific theory to explain many everyday problems ignored by us ↪ easy to understand ↪ cause our curiosities • The problems involved many regions e.g. daily activities, health care, history, food science But all of them can be explained by science

  5. Let’s us show you two interesting articles in the book!!!

  6. Why doesn't the 3 Second Glue adhere to the tube?

  7. What is 3 Second Glue • Generic Name: Cyanoacrylate • is used for gluing of various materials But why it doesn’t adhere to the tube?

  8. Firstly, let’s me tell you why 3 Second Glue can glue materials together!!! • Main component of 3 Second Glue: • Ethyl 2-cyanopropenoate (ECA) • (氰基丙烯酸酯) • a colourless liquid with low viscosity

  9. hydrogen atom oxygen atom

  10. Polymerization • (聚合作用)occurs!!! CH2(CN)CO2Et + CH2O ➩ CH2=C(CN)CO2Et + H2O

  11. The tube is made of plastic • separate the Ethyl 2-cyanopropenoate from the hydroxide ionsoutside • no polymerization occurs ↪ 3 Second Glue does not adhere to the tube

  12. We notice that... • Chemistry seems to be abstract to many students • But this article shows that Chemistry is related to our life • We have never noticed the reason why 3 Second Glue doesn't adhere to the tube ↪we should be more sensitive to our surroundings

  13. What are the differences among them? Green Tea Black (Red) tea Oolong tea

  14. Why do we choose this article ? They are similar to one another, aren’t they? Tea is the most widely consumed drink in the world But we don’t know much about it…… (we think that all the teas are the same)

  15. All real teas come from leaves of Camellia Sinensis But different processing methods produce different types of tea

  16. Green Tea • the result of curing the tender camellia leaf • various methods and degrees of heat can be use Green rooibos

  17. Green Tea • oxidation process is omitted • sundried foliages develop a yellow-tan colour • contains a substantially higher amount of phenolic phytochemicals and other antioxidants

  18. Red tea • is made by cutting to oxidize the foliages before sun drying

  19. Red tea The oxidation process turns the cut plant parts into reddish-orange colour Red rooibos

  20. Oolong tea • fully oxidised before drying by a careful withering process

  21. Oolong tea • the raw leaves are sun-wilted and then bruised • exposes their juices to the air • leaves oxidise➩ turn brown

  22. Now we know the differences among green tea, red tea and oolong tea ! Tea is classified based on the techniques with which it is produced and processed

  23. Also we find that tea benefits our health ! • Tea leaves contain more than 700 chemicals e.g. Green tea is rich in catechinpolyphenols, particularly in epigallocatechingallate (EGCG) • EGCG is a powerful anti-oxidant • inhibiting the growth of cancer cells • killing cancer cells without harming healthy tissue • lowering LDL cholesterol levels • inhibiting the abnormal formation of blood clots

  24. Group List Ng Wai Kwan (24) TseOi Chu (31) Tsui Yu Ping (32) Yai Ying Wai (38)

  25. End

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