Read and learn the following words. Translate the examples. To classify – классифицировать, делить на группы

to classify – классифицировать, делить на группы

classification – классификация

e.g. There are many different classifications of metals.

to base on – основывать на

composition – состав

e.g. There is a classification based on the composition of metals. Metals may be also classified according to their physical and chemical properties.

ferrous metal – черный металл

non-ferrous metal – цветной металл

e.g. Iron is a ferrous metal. Copper and aluminum are non-ferrous metals. Lead, zinc and tin are also non-ferrous metals.

to alloy – легировать, сплавлять

alloying element – легирующий элемент

e.g. An alloy consists of two or more metals and other elements.

to combine – соединять, сочетать

simple – простой

e.g. An alloy combines some elements. An alloy combinessimple metals with some other elements.

simple metal – простой металл

pure – чистый

pure metal – чистый (без примесей) металл

purity – чистота

impurity – примесь

e.g. Simple metals are usually pure chemical elements.

to produce – производить, изготавливать

product – изделие

production – производство, изготовление

e.g. In old time people did not know how to produce and how to use metals. Ferrous metals and alloys include a great number of commercially important products.

iron – железо

cast iron – чугун

grey cast iron – серый чугун

white cast iron – белый чугун

malleable cast iron – ковкий чугун

steel – сталь

carbon steel – углеродистая сталь

alloy steel – легированная сталь

stainless steel – нержавеющая сталь

e.g. Iron, alloy steels, carbon steels, stainless steels are commercially important products.

light – легкий

e.g. Light metals are aluminium (алюминий), titanium (титан), magnesium (магний), berillium (бериллий).

alkali metals – щелочные металлы

alkali earth metals – щелочноземельные металлы

e.g. The alkali metals and the alkali earth metals are also light metals.

to include – включать

heavy – тяжелый

e.g. Heavy metals include such metals as lead, tin, silver, copper, nickel (никель), zinc ( цинк). The heaviest metal is osmium (осмий).

rare metals – редкий металл

precious (= noble) metals – благородные металлы

refractory – огнеупорный, жаростойкий, тугоплавкий

refractory material – жаростойкий (огнеупорный) материал

refractory metal – тугоплавкий металл

refractory steel – жаростойкая сталь

to exhibit – проявлять (свойства, качества)

e.g. Refractory metalsexhibit high melting point. Their melting point is above 3000°F (1650°C).

low melting point metals – металлы с низкой точкой плавления

to resist – сопротивляться, противостоять

resistance – сопротивление, устойчивость

resistant – устойчивый, стойкий

corrosion resistant – коррозиостойкий

wear – износ

wear resistant – износостойкий

e.g. Some metals are corrosion and wear resistant. Corrosion resistance is a very useful property in a metal. All these metals exhibit great corrosion and wear resistance.

to vary – варьировать, различаться

hard – твердый

hardness – твердость

soft – мягкий

softness – мягкость

e.g. Metals vary in hardness and softness. Tin and lead are soft metals.

Potassium is so soft that it can be molded like wax (формироваться как воск), chromium is so hard that it can cut glass (резать стекло).

to group – группировать

to class – классифицировать (= to classify)

industrial application – промышленное применение

e.g. Metals may be grouped (= classed, classified) according to their industrial application. Metals are grouped into pure metals and alloys. Metals are often used in the form of alloys.

semi – полу

semimetals – полуметаллы

semiconductor – полупроводник.

2. What suffixes are used to derive nouns from verbs and adjectives? Form nouns and translate them.

to classify, to produce, hard, soft, to resist, pure.

3. Read the text «Classification of metals». Answer the following questions in Russian.

1) На какие группы делятся металлы в зависимости от их химической чистоты?

2) Как обычно делят металлы в современном промышленном производстве?

3) Что собой представляют черные металлы?

4) На какие подгруппы делятся черные металлы?

5) Какой из черных металлов является самым важным?

6) На какие 3 группы делятся чугуны?

7) Как делятся металлы в зависимости от их удельного веса?

8) О каких легких и тяжелых металлах вы узнали из текста?

9) На какие две подгруппы можно разделить цветные металлы?

10) Как делятся металлы в зависимости от их точки плавления?

11) Какие металлы относятся к тугоплавким?

12) О каких металлах с низкой температурой плавления Вы узнали из прочитанного текста?

13) Приведите пример твердого и мягкого металла.

14) Какие металлы относятся к полуметаллам?

Text С

CLASSIFICATION OF METALS

There are some classifications of metals based on their chemical purity, physical and chemical properties and composition, their industrial application (= use), etc.

According to (= in respect to; depending on) the chemical purity we may divide all metals into 2 large groups:

1. Simple metals which are more or less pure chemical elements.

2. Alloys which are materials consisting of a simple metal combined with some other elements.

In modern industry we usually divide metals into 2 main groups according to their chemical composition:

1. Ferrous metals; 2. Non-ferrous metals.

Metals consisting of iron combined with some other elements are known as ferrous metals; all the other metals are called non-ferrous metals. Ferrous metals and alloys include a great variety of (= very many) commercially important products which can be grouped into: a) iron (cast iron), b) саrbоn steels; c) alloy steels; d) stainless steels and other types of steels.

The most important ferrous metal is cast iron which is some form of alloy with carbon (C) and other elements. Cast iron finds greater use than аnу other metal. We may classify all cast irons into 3 groups: grey cast iron, white cast iron and malleable cast iron. In respect to their density metals may be divided into light and heavy ones. Metals having a density less than 4 are called light metals, all other having a density over 4 are known as heavy metals.

Light metals are aluminium, berillium, magnesium, titanium. The alkali metals and the alkali earth metals also belong to light metals. The alkali metals include such metals as lithium, sodium, potassium; the alkali earth metals include such metals as calcium, strontium and radium.

Heavy metals include such metals, for example, as lead, tin, silver, copper, nickel, zinc.

The lightest metal is lithium (D – 0.534) and the heaviest is osmium (D – 22.48).

Non-ferrous metals may in its turn bе subdivided into two groups:

a) the so-called group of rare metals (berillium, gallium, bismuth, germanium, selenium, tungsten, tantalum, molybdenum, cobalt, titanium, uranium, zirconium, etc.);

b) and the so-called group of precious (= noble) metals which include silver, gold, platinum, palladium and indium.

Metals may also be classified according to their melting point. Metals which exhibit (= have) high melting point above 3000°F (1650° C) are often called refractory metals. Refractory metals include such non-ferrous metals as tungsten, titanium, molybdenum, tantalum, and chromium. These metals also exhibit great corrosion and wear resistance and are very difficult to produce. The low melting point metals are rubidium, cesium which melts just above room temperature and mercury which melts at – 38, 8° C.

We may also classify hard and soft metals. For example, potassium is so soft that it can be molded like wax, and chromium is so hard that it can even cut glass.

Many elements are classed аs semimetals (arsenic, antimony and bismuth, for example) because they possess much poorer conductivity than true metals and may be classed with the semiconductors.

4. Read again the text "Classification of metals". Answer the following questions without looking into the text.

1) Into what groups may we divide metals according to their chemical purity?

2) What are a simple metals?

3) What is an alloy? What does it consist of?

4) Into what groups do we usually divide metals in modern industry?

5) How will you call metals consisting of iron combined with some other elements?

6) Into what groups may we divide ferrous metals?

7) What is the most important ferrous metal?

8) How are cast irons classified (into what groups)?

9) How are metals divided according to their density?

10) What are the densities of light metals (of heavy metals)?

11) What alkali and alkali earth metals do you know?