Lesson three Oral topic: in the chemical laboratory Grammar

Note:
* chemistry lab = laboratory work in chemistry;
* jot down = put down in short;
* Sheets = tables = charts.
Exercise 1. Find in the instruction sentences in imperative mood and translate them.
Exercise 2.

1. 
   Answer the questions.
   

1. 
   What kind of experiments do you carry out in the chemical laboratory?
   
2. 
   Is it necessary to use any equipment in these experiments? What equipment?
   
3. 
   What is necessary to know before going to lab?
   
4. 
   What must you know about safety equipment and safety data?
   

2. 
   Find in this instruction some rules of work in the laboratory. Do you agree that these rules help you perform your experiments successfully? Support your answer with some arguments.
   

Exercise 8. Look through the text again and summarize in your own words how students are supposed to prepare for the chemistry lab. Use the following phrases:
Firstly, secondly, thirdly … .
It is necessary (important) to … .
Not less important is … .
Everybody should know … .
It is evident that … .
Thus, these are … .


Use the following key words: pre-lab assignment; to use lab safety equipment; to understand the steps of the experiment; to fill out a laboratory book; to have necessary glassware, materials and chemicals; to know disposal procedures for the chemicals; after the experiment; to take data in the lab; to use clean lab coat and goggles.
Exercise 9. Tell your groupmates how you prepare for your chemistry lab.
Exercise 10. Read the text and compare two metric systems. What system do we use in our country?
Measurement – The Metric System
The metric system of measurement has several advantages over the English system. It has, therefore, been widely accepted as the system of measurement used by most countries throughout the world and by all scientists. One advantage is that the name often tells you how large a unit is. Such is not true for the English system. The word “mile” does not tell you it contains 5280 feet. In the metric system kilometer means 1000 meters. The same prefixes are used throughout and they tell you the size of the unit. The common prefixes are: