ТОП 10:

Answer the following questions using information given in Text A.



 

1) По каким двум основным совокупностям свойств мы делим химические элементы на металлы и неметаллы?

2) Каковы отличия металлов от неметаллов на основании физических свойств?

3) Каковы отличия металлов от неметаллов на основании химических свойств?

4) Какие свойства элементов имеют большее значение для отнесения того или иного элемента к металлам или неметаллам? Поясните Ваш ответ примерами из текста.

5) Сколько элементов таблицы Менделеева относятся к металлам?

 

Fill in the blanks with the following words: good, poor, sodium, salts, cathode, anode, high, ductile, positive, negative, malleable, brittle, graphite, mercury, potassium.

1) All metals are solid at room temperature except … .

2) Metals have a high density except … .

3) Non-metals are poor conductor of electricity except … .

4) Solid non-metals are ... while metals are … .

5) Metals always form ... ions while non-metals form ... ions.

6) When metals react with acids in result ... are formed.

7) During electrolysis metals are liberated at the ... while non-metals are liberated at the … .

8) Metals have ... melting points.

9) Metals are ... conductors of heat and electricity while non-metals are ... conductors of heat and electricity.

10) Metals can be drawn into wire, that is they are … .

 

6. Read and decide if the following statements are right or wrong. ("That's right"; "That's wrong").

 

1) All metals are solid at room temperature.

2) Non-metals usually have low density.

3) All non-metals are poor conductors of heat and electricity.

4) Non-metals react with dilute acids forming salts.

5) Metals form positive ions.

6) These positive ions are liberated at the anode during electrolysis.

7) Non-metals can be drawn into wire.

8) Not all metals have a high density.

9) Metals have high-melting points.

10) Graphite is a metal.

11) Potassium and sodium have a high density.

12) Most metals are liquid at room temperature.

13) Solid non-metals are brittle.

14) Physical properties are much more important for deciding whether this or that element is a metal or a non-metal.

 

7. Read again the text "Metals and Non-metals". Answer the following questions without looking into the text.

 

1) How many elements are there in the Mendeleyev's Periodic Таble?

2) What groups are these elements divided into?

3) What are the main differences between metals and non-metals:

- on the basis of their physical properties;

- on the basis of their chemical properties?

4) How many elements are considered to be metals?

5) What properties (physical or chemical) are much more important for deciding whether this or that element is a metal or non-metal?

 

Independent tasks

Write down all new words and phrases in your notebooks. Group them into sections: nouns, adjectives, verbs, and phrases. Learn these words and phrases for the next lesson.

Read additional texts about metals and retell them in Russian.

 

GOLD

It is supposed (полагают) that gold was the first of all metals used by man. Why did the ancient people want gold? They did not use it аs money. Other things had served for money long before gold was used. Most likely, they wanted gold only for ornaments (украшения). Gold is a wonderful metal in many ways. As you know, gold is a yellow metal, bright and shining when polished – the colour of the sun. Perhaps, gold seemed to the ancient people to be a piece of the sun found on the earth and all ancient gold – seeking people (золотоискатели) were worshippers (поклонниками) of the sun.

 

COPPER

Copper came after gold. Then came tin, lead, silver and iron. We know that copper and tin came into use some time before silver and lead and a long time before iron. Probably, it was in Egypt that man first found copper. In ancient times copper was used in the form of alloys-bronze and brass. As we know, an alloy is a mixture of two or more metals. Bronze is a mixcture of copper and tin. Brass is an alloy of copper and zinc (цинк). Sometimes silver is added to bronze when bells are cast (отливать колокола). It is believed that silver gives a clear tone. Throughout (за всю) history of the world copper and bronze have always been used for making works of art (произведение искусства).

 

LESSON 3

CLASSIFICATION OF METALS

Read and learn the following words. Translate the examples.

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.

 

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.

 







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