4. Language development.

1. Complete the following sentences.

1. Chemistry is the study of ... .

2. Matter exists in three different states ... .

3. There are two kinds of properties: ... .

1. All pure substances can be divided according to their composition into two ... .

2. Laboratory investigations of compounds follow two general tech­niques ....

3. Analysis is ... .

4. Synthesis means building ....

5. The difference between the quantitative and qualitative analyses is

6. The methods of quantitative analysis are ....

7. The methods of qualitative analysis are ... .

2. Answer the following questions.

1. What states of matter do you know?

2. What is the most important characteristic of a substance?

3. What are the two kinds of properties of substances?

4. What is the difference between the physical and chemical chan­ges?

5. What are the two kinds of laboratory investigations?

6. What is the difference between analysis and synthesis?

7. What is the difference between quantitative and qualitative ana­lysis?

8. What types of quantitative analysis do you know?

9. What types of qualitative analysis do you know ?

3. Match each word from column A with its opposite from column B.

A	B
1. to analyze	a. abscnce
2. permanent	b. to synthesize
3. to form	c. temporary
4. to dccomposc	d. to build up
5. pure	e. to stay without changes
6. to transform	f. dirty
7. prescncc	g. to rule out
8. to determine	h. to destroy
9. to identify	i. liquid
10. solid	j. not to recognize

4. Translate into English.

1. Дисоціація на іони відбувається в той час, коли розчиняється розчинник.

2. Іон — це атом або група атомів з однаковим електричним зарядом або зарядами.

3. Розчини кислот, основ та солей проводять електричний струм.

4. Слово іон походить від грецького слова.

5. Існує рівновага між дисоційованими та недисоційованими частками електроліту в розчині.

6. Іонізація — це зворотна хімічна реакція.

5. Read the text and entitle it.

All the matter consists of atoms. Exceptional kinds of matter are the elementary panicles from which they are made (electrons, protons, neutrons) and similar sub-microscopic particles (positrons, mesons). Atoms are the structural units of all solids, liquids and gases. An atom consists of a central nucleus plus one or more electrons. Nucleus is small, heavy, with positive electrical charge. Electron is light, with negative electrical charge. An aggregation of atoms forms a molecule. Molecules of different chemical substances contain varying numbers of atoms, bonded very tightly together. Therefore the number of atoms in a molecule varies with the compound. A symbol is used to represent an atom of an element, as well as the element itself.