3. Read and translate the sentences paying attention to the words with the root mean.

mean (meant) v – означать, значить

meaning n – значение

mean adj – средний, средней величины

means n – способ, средство

by means of prep – посредством, при помощи

by no means – никоим образом; нисколько

by all means – любым способом

1. The scientists must find the means to measure the temperature of the liquid.

2. The solubility of a substance means the amount of that substance which dissolves in a particular solvent.

3. The formulas of compounds are determined by chemical means.

4. We transform the liquid into solid by means of freezing.

5. The mean temperature inside this apparatus is +100 ºC.

6. The term “matter” has some meanings.

7. The behaviour of the substance is by no means certain.

8. Researchers in the laboratory will define the properties of the new plastics by all means.

9. Radiation means the production of energy waves.

4. Read and translate the text, say what its main points are. Study the vocabulary notes after the text.

CHEMISTRY AS A SCIENCE

Chemistry is a very large and complex science. The origin of chemistry goes back to ancient times. It is associated with the manufacture of bronze, iron, ceramics and glass. Sufficient facts, entirely free of magic¹ which surrounded the work of the alchemists, appeared at the end of the sixteenth century.

In the seventeenth century modern chemistry began with the work of Robert Boyle. Later A. Lavoisier introduced the concept of chemical elements. In 1869 D. I. Mendeleyev discovered regularities in the properties of elements. In the nineteenth century A. Avogadro introduced the concept of molecules.

So, many great scientists devoted their lives to the development of chemistry: M. Curie, N. Bohr, M. V. Lomonosov, D. I. Mendeleyev, A. M. Butlerov, F. A. Kekule, N. N. Semyonov should be mentioned among them.

Modern chemistry is the experimental and theoretical study of matter. Chemistry deals with the composition and properties of matter, the changes and transformations it undergoes, the conditions under which such changes take place, and the energy changes which accompany them.

A chemical change is the conversion of one substance into another. This involves changes in composition and properties of matter. Chemical changes are usually accompanied by the liberation or absorption of energy in the form of light, heat or electricity.

All forms of matter consist of either pure substances or mixtures of two or more pure substances. The building blocks of matter are elements. The combinations of elements are called compounds. Most of the elements are metals, and most of them are able to unite with other elements and form compounds in that way.

The formation of a compound from simpler substances is known in chemistry as synthesis. The process of breaking down a compound into simpler substances or its elements is called analysis. In other words, analysis means the determination of the composition of a compound. It is necessary to remember that the composition of a pure substance never changes.

Matter exists in three common states: the solid, the liquid and the gaseous state. Solids have both a definite volume and a definite shape. Liquids have a definite volume but no definite shape, taking the shape of the container they are in. Gases have neither a definite volume nor a definite shape: they take the volume and the shape of their containers.

A matter usually can be transformed from one state to another under the changes of its temperature. The change of liquid matter into vapour (i. e. gaseous state) is known as evaporation. The process of transforming solid into liquid state is called melting. When liquid is converted into solid the process is defined as crystallization. The state of matter is changed by means of heating, cooling or freezing it. A change in the state or form of a substance is a physical change.

To characterize matter it should be mentioned that² every substance has physical and chemical properties. Physical properties include colour, smell, solubility, density, hardness, boiling and melting points. Chemical properties of a substance include its behaviour with other materials.

Chemistry is one of the fundamental sciences. Everyone understands the significance of chemistry. It plays an important part in the development of biochemistry, physics, medicine, geology and many other fields of science. The future of chemistry is practically unlimited.

Vocabulary notes:

¹ entirely free of magic – полностью лишенные магической составляющей

² it should be mentioned that – следует упомянуть о том, что