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《Writing》优质课PPT课件下载
Aim
The aim of this experiment is to remove the shell from an egg without breaking the egg.
Equipment
To carry out the experiment, you will need the following things: a glass, a small saucepan, water, an egg and about 250ml of vinegar.
Method
First, boil the egg for about fifteen minutes in a saucepan of water. Next, place the egg in the glass and cover it with the vinegar. After that, leave the egg in the vinegar for 24 hours.
Result
Oberserve the egg carefully. At first you will see bubbles of gas forming on its surface. This gas is carbon dioxide. After 24 hours, the shell will disappear completely.
Conclusion
The egg shell is made of calcium carbonate and the vinegar is an acid. The two substances react to form the gas carbon dioxide and the egg shell disappears.
2CH3COOH+CaCo3=(CH3COO)2Ca+CO2↑+H2O
Write a description of the experiment
Aim
The aim of this experiment is to…
Equipment
You will need…
Method
First, dip your pens into the water…
Next, write…
After that,…
Finally,…
Result
The message…
Conclusion
The message appears when you spray the water…