introduction of the book article 1 : why doesn't the 3 second glue adhere to the tube? article...
TRANSCRIPT
• 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?
Content
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
• Dr. Joe used simply scientific theory to explain many everyday problems ignored by us ↪ easy to understand ↪ cause our curiosities
• The problems involved many regionse.g. daily activities, health care, history, food
science
But all of them can be explained by science
Why did we find it interesting
What is 3 Second Glue• Generic Name:
Cyanoacrylate• is used for
gluing of various materialsBut why it
doesn’t adhere to the tube?
• Main component of 3 Second Glue:
Ethyl 2-cyanopropenoate (ECA)
(氰基丙烯酸酯 )• a colourless liquid with low
viscosity
Firstly, let’s me tell you why 3
Second Glue can glue materials
together!!!
ECA directly contacts with the air when pressed out of the tube
reacts with the hydroxide ions (OH– 氫氣根離子 ) in the water vapour in the air
long, strong chains are formed
join the bonded surfaces together
oxygen atom
hydrogen atom
• The tube is made of plastic• separate the Ethyl 2-
cyanopropenoate from the hydroxide ions outside
• no polymerization occurs ↪ 3 Second Glue does not
adhere to the tube
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
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)
WHY DO WE CHOOSE THIS ARTICLE ?
They are similar to one another, aren’t they?
All real teas come from leaves of Camellia Sinensis
But different processing methods produce different types of tea
Green Teathe result of curing the
tender camellia leaf various methods and
degrees of heat can be use
Green rooibos
GREEN TEAoxidation process is omittedsundried foliages develop a
yellow-tan colour contains a substantially higher
amount of phenolic phytochemicals and other antioxidants
Oolong tea
• the raw leaves are sun-wilted and then bruised
• exposes their juices to the air
• leaves oxidise ➩ turn brown
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
Also we find that tea benefits our health !
Tea leaves contain more than 700 chemicals e.g. Green tea is rich in catechin polyphenols, particularly in epigallocatechin gallate (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