English for chemistry use for the students of chemistry in the education faculty of AGU

A water molecule consists of an oxygen atom and two hydrogen atoms.. An atom is the smallest unit of an element that has the 2 _________of the element; a molecule is the smallest unit of

With the obstacles mentioned above, AGU determined to ask for the introduction of some English for Special Purposes (ESP) course books and specifically English for Chemistry for the students of chemistry in the

Education Faculty of AGU

According to the definition of English for Specific Purposes (Tom Hutchinson and Alan Walters, 1990 - CUP), ESP is an approach to language teaching in which all decisions as to content and method are based on the learners’ reasons for learning All of the learners need to learn to use a specific area of the English language in the shortest term possible (the other aspects of language should not be ignored!) Therefore, after identifying a target situation - the need for a specific segment at the College - the learners have to be identified; their situation and the target situation are then analyzed The learners’ potentials are identified, as well as the skills and

knowledge needed to attain the target situation - taking constraints, such as aptitude, time and technical

resources, into consideration With these data in mind, a course is designed and the materials are then chosen or specially designed Evaluation is a very important tool so that strategies can be redefined and results improved The authors of this English for Chemistry course-book intend to use it as a bridge to link the General English textbooks afore-learned and their future specialized –major materials That means this course book also focuses

on 4 integrated skills: Listening (10%); Speaking (10%); Reading (60%); Writing (20%) This course book

provides some very basic terms of chemistry in English with essential vocabulary in simply comprehensive texts Obviously, the composition of this course book has some fundamental differences in comparison with other ESP course books compiled in many other Vietnamese universities, which just focus on 2 major skills – Reading and Grammar Skills

Why do we intend to do so? Because we think that in addition to helping students understand the texts due to key words, we would like to offer the learners more opportunities to get familiar with native speakers’ accents in some texts Therefore, they can improve their English pronunciation and they may remember new words longer These memorized new words will help them a lot when they read their own specializing materials

Following is the outline of the course book:

Finally, the authors of this course book appreciate so much all positive comments from teachers of chemistry, students of chemistry and other readers who are interested in chemistry so that this course book will be improved, and we hope that the students of chemistry at AGU will have much success in their studies

PART ONE GENERAL CHEMISTRY

UNIT 1

Introduction to Chemistry

Chemistry for Life

Over the last two centuries, chemistry has changed our daily lives more than any other of the sciences Chemistry makes our world more colorful, more efficient, more reliable and safer Pharmaceuticals, cosmetics, toiletries and body-care products, airbags and brake fluid -

they're all chemical products Of all the natural sciences, this is the only one to have given rise

to an entire industry - in Europe alone, approx 1.7 million people are currently employed in the chemical industry Without doubt, chemistry will go on into the 21st century as the key science within newly evolving areas of knowledge and interdisciplinary research

At the same time, however, no other science is connected with more bad emotions, refusal and anxiety across wide sectors of society

Chemistry in everyday life

"Every thing we wear is touched by the hands of the chemist The music we hear is touched

by the hand of the chemist The perfume in the air in Washington cocktail parties is all

chemicals Chemistry is not going to go away What we do have to do is to make sure that both chemists and non-chemists know a responsible way of working with chemistry and everything that it can do for us."

Sylvia Ware American Chemical Society, Washington, D.C

c a cleansing substance

d water containing a significant amount of salt (esp used for curing)

e chemical substance for killing unwanted plant

f a characteristic quality of something

g proving that something is true

h a response to the physical effects of something

i to produce something as a result of

j changing a substance from one state to another

o to make an exact copy of

something

Chemistry is study of the composition, structure, properties, and interactions of matter

Chemistry arose from attempts by people to transform metals into gold beginning about AD

100, an effort that became known as alchemy Modern chemistry was established in the late

18th century, as scientists began identifying and verifying through scientific experimentation

the elemental processes and interactions that create the gases, liquids, and solids that compose our physical world As the field of chemistry developed in the 19th and 20th centuries, chemists learned how to create new substances that have many important applications in our lives

Chemists, scientists who study chemistry, are more interested in the materials of which an object is made than in its size, shape, or motion Chemists ask questions such as what happens

when iron rusts, why iron rusts but tin does not, what happens when food is digested, why a

solution of salt conducts electricity but a solution of sugar does not, and why some chemical changes proceed rapidly while others are slow Chemists have learned to duplicate and

produce large quantities of many useful substances that occur in nature, and they have created substances whose properties are unique

Much of chemistry can be described as taking substances apart and putting the parts together again in different ways Using this approach, the chemical industry produces materials that are vital to the industrialized world Resources such as coal, petroleum, ores, plants, the sea, and

the air yield raw materials that are turned into metal alloys; detergents and dyes; paints,

plastics, and polymers; medicines and artificial implants; perfumes and flavors; fertilizers,

herbicides, and insecticides Today, more synthetic detergent is used than soap; cotton and

wool have been displaced from many uses by artificial fibers; and wood, metal, and glass are often replaced by plastics

Chemistry is often called the central science, because its interests lie between those of physics (which focuses on single substances) and biology (which focuses on complicated life processes) A living organism is a complex chemical factory in which precisely regulated reactions occur between thousands of substances Increased understanding of the chemical behavior of these substances has led to new ways to treat disease and has even made it possible to change the genetic makeup of an organism For example, chemists have produced

strains of food plants that are hardier than the parent strain

Because the field of chemistry covers such a broad range of topics, chemists usually specialize Thus, chemistry is divided into a number of branches Nevertheless, the process of

learning the properties of a substance and of taking it apart is fundamental to nearly all of

gas causes physical changes Another example of physical change is the melting of ice, in

which water changes from the solid to the liquid state

Salt and water may not only be separated when in solution, but each may be broken down into other substances This, however, involves a different kind of change—one that usually requires more energy than a physical change and that alters the fundamental nature of the material This type of change is called a chemical change By applying electrical energy, water can be broken down into two gases, hydrogen and oxygen Hydrogen is a light gas that

burns; oxygen is a gas that is necessary to sustain animal life Salt can be broken down by

melting it, then passing an electric current through it This produces a pungent yellow-green gas called chlorine and a soft, silvery metal called sodium, which burns readily in air

Some materials can be broken down simply by heating them Other materials yield to attack

by another substance; for example, iron oxide ore heated with coke yields metallic iron

™ READING COMPREHENSION:

Read the passage above and check whether the following statements are true (T) or false (F)

1 □ Modern chemistry was established in the early 18th century

2 □ Chemists in the 19th and 20th centuries learned how to create new substances that have many important applications in our lives

3 □ Wood, metal, and glass are often replaced by synthetic detergent

4 □ Chemistry is often called the central science, because its interests lie between those of physics and philosophy

5 □ Getting the salt out of seawater is an example of biological change

6 □ “Salt and water may be broken down into other substances” is another

example of physical change

7 □ Water can be broken down into two gases, hydrogen and oxygen

8 □ Almost all materials can be broken down simply by heating them

9 □ Water changing from the solid to the liquid state is called the evaporation process of water

10 □ Electric current is not likely to pass through salt when it is melting

STRUCTURE STUDY

I Comparative Adjectives

When we talk about two things, we can "compare" them We can see if they are the same or different Perhaps they are the same in some ways and different in other ways We can use comparative adjectives to describe the differences

We can use comparative adjectives when talking about two things (not three or more things)

In the example below, "bigger" is the comparative form of the adjective "big":

In this lesson we will look first at how we make comparative adjectives, and then at how we use them:

Formation of Comparative Adjectives

There are two ways to make or form a comparative adjective:

• short adjectives: add "-er"

• long adjectives: use "more"

Short adjectives

• 2-syllable adjectives ending in -y

happy, easy

Normal rule: add "-er" old > older

Variation: if the adjective ends in -e, just add -r late > later

Variation: if the adjective ends in consonant, vowel, consonant,

Variation: if the adjective ends in -y, change the y to i happy > happier

Long adjectives

• 2-syllable adjectives not ending in -y

modern, pleasant

• all adjectives of 3 or more syllables expensive, intellectual

Normal rule: use "more" modern > more modernexpensive > more

expensive

With some 2-syllable adjectives, we can use '-er' or 'more':

• quiet > quieter/more quiet

• clever > cleverer/more clever

• narrow > narrower/more narrow

• simple > simpler/more simple

Use of Comparative Adjectives

We use comparative adjectives when talking about 2 things (not 3 or 10 or 1,000,000 things, only 2 things)

Often, the comparative adjective is followed by "than"

Look at these examples:

• John is 1m80 He is tall But Chris is 1m85 He is taller than John

• America is big But Russia is bigger

• I want to have a more powerful computer

• Is French more difficult than English?

If we talk about the two planets Earth and Mars, we can compare them as shown in the table below:

Diameter (km) 12,760 6,790 Mars is smaller than Earth

Distance from Sun (million

km)

150 228 Mars is more distant from the Sun

Length of day (hours) 24 25 A day on Mars is slightly longer than a day on Earth

Surface temperature (°C) 22 -23 Mars is colder than Earth

Although we use comparative adjectives when talking about two things (not three or more

things), in fact one or both of the things may be a group of things

• Mt Everest is higher than all other mountains

Here, we are talking about hundreds of mountains, but we are still comparing one thing (Mt Everest) to one other thing (all other mountains)

EXERCISE # 1

Rewrite the following sentences without changing their meanings Example: The atomic weight of oxygen is heavier than the atomic weight of carbon

The atomic weight of carbon is lighter than that of oxygen

1 Hydrogen gas is much lighter than air

Air

2 Chemistry has changed our daily lives more than any other of the sciences

Any other of the sciences _

3 More synthetic detergent is used than soap

II DOUBLE COMPARATIVES

The sentences begin with a comparative construction, and thus the second clause must also begin with a comparative

The + comparative + subject + verb + the + comparative + subject + verb

Example:

The hotter it is, the more miserable I feel

The higher we flew, the worse Edna felt

The bigger they are, the harder they fall

The sooner you take your medicine, the better you will feel

The sooner you leave, the earlier you will arrive at your destination

The more + subject + verb + the + comparative + subject + verb

Example:

The more you study, the smarter you will become

The more he rowed the boat, the farther away he got

The more he slept, the more irritable he became

EXERCISE # 2: Use the double comparative to write 5 sentences about yourself or

about anything you like

UNIT 2

Elements and compounds

More than 100 chemical elements—substances that cannot be decomposed or broken into

more elementary substances by ordinary chemical means—are known to exist in the universe However, several of these elements, such as the so-called transuranium elements, have not been found in nature and can only be produced artificially

Russian chemist Dmitri Ivanovich Mendeleyev and German physicist Julius Lothar Meyer independently developed the periodic law of the chemical elements at about the same time in

the late 19th century Mendeleyev is generally credited with the findings, because he

established the periodic law in 1869, and Meyer established this chemical law in 1870 Both discovered that arranging the elements in order of increasing atomic mass produced a table of chemical properties and reactivity patterns that were regularly repeated This phenomenon—known as the periodic law—is most often represented in the periodic table of the elements

Read the two paragraphs above and answer the following questions

1 What are chemical elements?

2 Have all chemical elements been found in nature?

3 Is Meyer a German chemist?

4 Is Mendeleyev a Russian chemist?

5 What is the peiodic law?

I ELEMENTS

Hydrogen, oxygen, chlorine, sodium, and iron are examples of elements Elements cannot be

resolved into simpler substances by ordinary heat, light, electricity, or attack by other

substances To say that elements can never be broken down would not be accurate, but breaking them down takes millions of times more energy than can be applied by ordinary

means It requires either special equipment, such as a particle accelerator, or temperatures like those in the interior of the sun An element can therefore be defined as a substance that

cannot be broken down into simpler substances by ordinary means

Ninety elements are known to occur in nature, and 22 more have been made artificially Out

of this limited number of elements, all the millions of known substances are made

Abbreviating the names of the elements is often convenient For each element, a symbol has been chosen that consists of one or two letters The symbols are derived from the names of

the elements; for example, H stands for hydrogen, He for helium, C for carbon, and so on The abbreviations are not always derived from the English names, however The symbol Fe

for iron comes from the Latin ferrum, and W for tungsten comes from the German wolfram

These symbols are internationally recognized and are used even by people whose native languages do not use the Roman alphabet, such as Russian and Japanese

II COMPOUNDS

Water Molecule

Water is an example of a compound A water molecule consists of an oxygen atom and two hydrogen atoms Salt, water, iron rust, and rubber are examples of compounds A compound is made up of

elements, but it looks and behaves quite differently, as a rule, from any of its component

elements Iron rust, for example, does not look and feel like its components: oxygen gas and iron metal Some synthetic fabrics, with fibers made from coal, air, and water, do not feel at all like any of the components that make them up This individuality of properties, as well as other qualities, distinguishes a compound from a simple mixture of the elements it contains Another important characteristic of a compound is that the weight of each element in the compound always has a fixed, definite ratio to the weight of the other elements in the compound For example, water always breaks down into 2.016 parts of hydrogen by weight to 16.000 parts of oxygen by weight, which is a ratio of about 1 to 8, regardless of whether the water came from the Mississippi River or the ice of Antarctica In other words, a compound has a definite, invariable composition, always containing the same elements in the same proportions by weight; this is the law of definite proportions

Many elements combine in more than one ratio, giving different compounds In addition to

forming water, hydrogen and oxygen also form hydrogen peroxide Hydrogen peroxide 1 has 2.016 parts of hydrogen to 32 parts of oxygen; that is, 1.008 parts of hydrogen to 16 parts of oxygen Water, as stated above, has 2.016 parts of hydrogen to 16 parts of oxygen The figure 2.016 is twice 1.008 This example illustrates the law of multiple proportions: When two elements combine to form more than one compound, the element whose mass varies combines with a fixed mass of the second element weights in a simple whole-number ratio such as 2:1, 3:1, or 3:2

™ READING COMPREHENSION

Read the text and choose the correct answer for each item

1 Which of the followings is NOT an example of elements?

A electricity B chlorine C sodium D oxygen

1hydrogen peroxide (H2O2), a colourless liquid usually produced as aqueous solutions of various strengths, used principally for bleaching cotton and other textiles and wood pulp, in the manufacture of other chemicals, as a rocket propellant, and for

2 Which of the following statements is NOT correct?

A The symbol Fe for iron comes from the English ferrum

B The symbol Fe for iron comes from the Latin ferrum

C The symbol Fe for iron comes from the Roman ferrum

D The symbol Fe for iron comes from the French ferrum

3 Which of the followings is NOT an example of compounds?

4 The pronoun “it” in line 2 is likely to replace

5 The ratio of about 1 to 8 is the ratio of

A Hydrogen B Oxygen C carbon dioxide D water

STRUCTURE STUDY

Active Voice & Passive Voice

There are two special forms for verbs called voice:

1 Active voice

2 Passive voice

The active voice is the "normal" voice This is the voice that we use most of the time You are probably already familiar with the active voice In the active voice, the object receives the

action of the verb:

subject verb object

active

Cats eat fish

The passive voice is less usual In the passive voice, the subject receives the action of the

The object of the active verb becomes the subject of the passive verb:

active Everybody drinks water

EXERCISE # 1

Rewrite the following sentences without changing their meanings

Example: Mendeleyev established the periodic law in 1869

The periodic law was established by Mendeleyev in 1869

1 People often call chemistry the central science

People have not _.

4 Breaking elements down takes millions of times more energy than can be applied by ordinary means

Millions of times more _

5 Elements cannot be resolved into simpler substances by ordinary heat, light, electricity,

or attack by other substances

People cannot _

_

6 People internationally recognize the symbols of elements

The symbols

7 The symbols of elements are used even by people whose native languages do not use the Roman alphabet, such as Russian and Japanese.

UNIT 3 Atoms

I

An atom is a tiny, tiny bit of matter It’s really hard to imagine how small an atom is Suppose you could line atoms up in row It would take 100 million atoms to make a row only 1 centimeter long

Everything in the world is made of atoms The chair you are sitting on, the computer you are looking at, the clothes you are wearing, and even your body are all made of atoms

There are more than 100 kinds of atoms Each kind of atom belongs to a different element, such as oxygen or iron An element is the simplest kind of substance there is, made up of only one kind of atom Oxygen is the element made up of only oxygen atoms Iron is the element made up of only iron atoms

II _

All atoms have the same basic parts Most of the matter in an atom is at its center, which is called the nucleus The nucleus of nearly all atoms is made of two more parts called protons and neutrons Protons and neutrons consist of even tinier parts called quarks

Electrons whirl around the nucleus but at some distance The distance between electrons and the nucleus means that most of an atom is empty space Scientists do not think that electrons are made of any more parts

Each type of atom has a different combination of protons, neutrons, and electrons The number of protons determines what kind of chemical element the atom is The difference in number of protons explains why oxygen differs from iron

III _

Atoms are not (1) new discovery Ancient Greeks came up (2) the idea

of atoms around 400 bc But the (3) _ Greeks did not understand what atoms were really (4) _ Scientists (5) _ many discoveries about the structure and

nature of atoms (6) _ the 1900s They used big machines (7) atom smashers, or particle accelerators, to smash parts of atoms together Then they studied the pieces They learned (8) powerful forces hold each tiny atom (9) _ They learned how to release this power called (10) _ energy or nuclear energy They built atomic bombs using this energy They also built (11) power plants that use atomic energy to make (12) _

I Understanding the organization of the text: Choose the three appropriate

headlines of the following list to put in order according to the text

1 Who discovered atoms?

2 How many kinds of atoms are there?

3 What is an atom?

4 What determines the type of chemical element?

5 Do atoms have parts?

6 What is the component of eletrons?

II Read part III of the text carefully again and choose the best word for each number to complete

3 A antique B ancient C ancestor D old

7 A called B calling C call D calls

9 A another B one another C each other D together

12 A electric B electronics C electricity D electrical

III LISTENING: Listen to the following text TWO TIMES and fill in the missing

words you hear for each blank (Blank 4 and 13 can be filled in two words)

Atoms and Molecules

The concepts of atoms and of the groups of linked atoms called (1) are the foundation of all chemistry An atom is the smallest unit of an element that has the (2) _of the element; a molecule is the smallest unit of a compound or the form of an element in which atoms bind together that has the properties of the compound or element

The idea of atoms is an old one (3) philosopher Leucippus and his student Democritus appear to have originated the idea during the (4)* centuries

BC According to them, matter consisted of small, indivisible particles called atoms All atoms were made of the same basic material, but neither (5) stated what this material was The atomic theory was developed further by another Greek philosopher, Epicurus, who

added the property of (6) _ to the atoms and attributed a horizontal, as well as a

vertical, motion to them in order to explain how atoms combine to form matter These ideas were restated by Roman poet Lucretius in the 1st century BC

In the (7) _, English schoolmaster John Dalton developed his well-known atomic theory, which explained the laws of definite and multiple proportions Convincing proof that atoms exist, however, has only been (8) _ since 1900 Much, but not all, of this proof came from the study of (9) and of energetic particles When Lucretius watched dust particles dancing in a (10) _and said that they were being battered by the (11) _ blows of restless atoms, he was basically right True, most of the dancing was caused by air currents, yet even in still air, specks of dust or smoke are in constant (12) _, as are minute particles suspended in water This constant random movement of particles is the so-called Brownian motion Two thousand years after Lucretius, (13)* Jean-Baptiste Perrin, armed with a microscope and, more importantly, a mathematical theory, measured the random motions of suspended dye particles and calculated the number of the invisible molecules whose (14) were causing the visible dye particles to move This way of counting molecules helped (15) _ the existence of atoms and molecules

EXERCISE

Rewrite the following sentences without changing their meanings

Example: Mendeleyev established the periodic law in 1869

The periodic law was established by Mendeleyev in 1869

1 Atoms make of everything in the world

Epicurus,

6 English schoolmaster John Dalton developed his well-known atomic theory, which

explained the laws of definite and multiple proportions

The well-known atomic theory _

_

7 A change in just one atom can make a big difference

A big

8 If you add just one more oxygen atom to carbon monoxide, you get carbon dioxide, a

harmless gas that plants need to make food

One more oxygen atom _

UNIT 4 Molecules

A

Did you ever wonder what things are made of? Some objects are hard Some are soft Some things you can pour The reason materials are different is because they are made of different bits called molecules Molecules are so tiny that you cannot see them Molecules are made of even tinier things called atoms Two or more atoms link together to make a molecule You and all things around you are made of molecules and atoms

B _

There are millions of different kinds of molecules Some molecules are made of only one kind

of atom A molecule of oxygen gas is made of two oxygen atoms Oxygen is a gas in air that all animals must breathe in order to live

Most molecules are made of more than one kind of atom One atom of oxygen and two atoms

of hydrogen, for example, make a molecule of water

Molecules come in all shapes and sizes Water is a small molecule Molecules that make up the plastic in a picnic fork are huge molecules made of many kinds of atoms

C

The atoms in a molecule determine what material the molecule is A change in just one atom can make a big difference Two oxygen atoms make one molecule of pure oxygen gas But one oxygen atom and one carbon atom make a molecule of carbon monoxide Carbon monoxide is a deadly poisonous gas If you add just one more oxygen atom to carbon monoxide, you get carbon dioxide, a harmless gas that plants need to make food

D _

Some molecules are found in nature Millions of natural molecules join together to make up the cells in plants and animals The food you eat, the air you breathe, and the cotton clothes you wear are made of natural molecules

Some molecules are made by scientists The paint on your walls and the dye that colors your T-shirt come from molecules made by scientists

I Understanding the organization of the text: Choose the three appropriate

headlines of the following list to put in order according to the text

1 WHERE DO MOLECULES COME FROM?

2 WHAT KINDS OF MOLECULES ARE THERE?

3 INTRODUCTION

4 WHAT’S THE DIFFERENCE BETWEEN MOLECULES?

II Reading Comprehesion: Read and text again and check whether the

following statements are true (T) or false (F), and write T or F on the line on the right after each statement

1 All the subjects are hard and soft _

3 Molecules determine what material the molecule is _

5 The dye that colors our T-shirt come from artificial molecules _

SRUCTURE STUDY: Adjective Clauses

An adjective clause is a dependent clause which takes the place of an adjective in another clause or phrase Like an adjective, an adjective clause modifies a noun or pronoun,

answering questions like "which?" or "what kind of?" Consider the following examples:

Adjective

the red coat

Adjective clause

the coat which I bought yesterday

Like the word "red" in the first example, the dependent clause "which I bought yesterday" in the second example modifies the noun "coat." Note that an adjective clause usually comes

after what it modifies, while an adjective usually comes before

In formal writing, an adjective clause begins with the relative pronouns "who(m)," "that," or

"which." In informal writing or speech, you may leave out the relative pronoun when it is not

the subject of the adjective clause, but you should usually include the relative pronoun in formal, academic writing:

Some firefighters never meet the people whom they save

Here are some more examples of adjective clauses:

the meat which they ate was tainted

This clause modifies the noun "meat" and answers the question "which meat?"

about the movie which made him cry

This clause modifies the noun "movie" and answers the question "which movie?"

they are searching for the one who borrowed the book

The clause modifies the pronoun "one" and answers the question "which one?"

Did I tell you about the author whom I met?

The clause modifies the noun "author" and answers the question "which author?

EXERCISE

Write the second sentence so that it does not change its meaning, with given words

Example: You eat food It is made of natural molecules

The food that you eat is made of natural molecules

1 We breathe air It is made of natural molecules

The air of natural molecules

2 You wear the cotton clothes They are made of natural molecules

The cotton clothes of natural molecules

3 Scientists make the paint The paint is on your walls

The paint made by scientists

4 Scientists make the dye Your T-shirt is coloured with the dye

The dye made by scientists

5 Chemists are scientists They study chemistry

Chemists chemistry

6 You are made from molecules and atoms All things are made from molecules and atoms

You and _ from molecules and atoms

7 Oxygen is an element It is made of only oxygen atoms

Oxygen is _ atoms

8 Chemistry is a branch of scientific study It studies the composition, structure,

properties, and interactions of matter

The compositon , structure

UNIT 5 Metals and Nonmetals

Metallic Bonding

Silver, a typical metal, consists of a regular array of silver atoms that have each lost an electron to form a silver ion The negativly charged electrons distribute themselves throughout the entire piece of metal and form nondirectional bonds between the positive silver ions This arrangement, known as metallic bonding, accounts for the characteristic properties of metals: they are good electrical conductors because the electrons are free to move from one place to another, and they are malleable (as shown here) because the positive ions are held together by nondirectional forces A force applied to a malleable substance shifts the positions of the atoms without breaking the bonds that hold them together

I LISTENING: Listen to the following recording TWO TIMES and

check whether the following statement are true (T) or false (F) on the line after each statement

1 The structure of the atom is not responsible for the physical differences between

3 All metals tend to easily lose some of the electrons on outer shells _

4 “Loose” electrons can not enable metals to conduct electricity _

5 Nonmetals tend to add electrons to achieve the state of a stable noble gas

_

II READING COMPREHENSION

Metal

Metal is any of a class of substances characterized by high electrical and thermal conductivity

as well as by malleability2, ductility3,and high reflectivity of light

Approximately three-quarters of all known chemical elements are metals The most abundant varieties inthe Earth's crust4 are aluminum, iron, calcium, sodium, potassium, and magnesium The vast majority of metals are found in ores (mineral-bearing substances), but a few such as copper, gold, platinum, and silver frequently occur in the free state because they do not readily react with other elements

Metals are usually crystalline solids In most cases, they have a relatively simple crystal structure distinguished by a close packing of atoms and a high degree of symmetry Typically, the atoms of metals contain less than half the full complement of electrons in their outermost shell Because of this characteristic, metals tend not to form compounds with each other They

do, however, combine more readily with nonmetals (e.g., oxygen and sulfur), which generally have more than half the maximum number of valence electrons Metals differ widely in their chemical reactivity The most reactive include lithium, potassium, and radium, whereas those

of low reactivity are gold, silver, palladium, and platinum

The high electrical and thermal conductivities of the simple metals are best explained by reference to the free-electron theory According to this concept, the individual atoms in such metals have lost their valence 5electrons to the entire solid,and these free electrons that give rise to conductivity move as a group throughout the solid In the case of the more complex metals (i.e.,the transition elements), conductivities are better explained by the band theory, which takes into account not only the presence of free electrons but also their interaction with so-called electrons

The mechanical properties of metals, such as hardness, ability to resist repeated stressing (fatigue strength), ductility, and malleability, are often attributed to defects or imperfections in their crystal structure The absence of a layer of atoms in its densely packed structure, for example, enables a metal to deform6 plastically, and prevents it from being brittle7

Nonmetal

Nonmetal is any substance that does not exhibit8 such characteristic properties of metals as hardness, mechanical adaptability, or the ability to conduct electricity This classification is

2 malleability:ability of being extended or shaped by beating with a hammer or by pressure of rollers

3ductility: capability of being drawn out or hammered thin

4 crust: a hard surface layer (as of soil or snow)

5 valence:the degree of combining power of an element as shown by the number of atomic weights of a univalent element (as

hydrogen) with which the atomic weight of the element will combine or for which it can be substituted or with which it can

be compared

6 deform:to alter the shape of by stress

7 brittle: easily broken, cracked, or snapped

generally applied to the chemical elements carbon, nitrogen, phosphorus, oxygen,sulfur, selenium, fluorine, chlorine, bromine, iodine,and the noble-gas elements These elements have few physical properties in common; most are gases, one (bromine) is liquid, and others are solids

The atoms of nonmetals generally are small and contain relatively large numbers of electrons

in their outermost shells In the noble-gas atoms, the electron shells are completely filled; thus, the elements are almost completely inert The other nonmetals have nearly filled electron shells, requiring only a few additional electrons to assume the stable, noble-gas configuration9 Therefore, in the presence of other atoms, these nonmetallic atoms have pronounced tendencies to attract electrons to themselves (high electronegativities) They form chemical compounds by attracting electrons away from other atoms of lower electronegativities or by sharing electrons with atoms of comparable electronegativities

Although there are only a few nonmetallic elements, they constitute a large portion of the Earth's crust and are essential for the growth and existence of living things

Read the text above and check whether the following statements are true (T) or false (F)

1 □ Metal is characterized by high electrical and thermal conductivity but low

reflectivity of light

2 □ Approximately one-quarters of all known chemical elements are nonmetals

3 □ Metals tend not to form compounds with each other but with nonmetals

4 □ The absence of a layer of atoms in their structure enables a metal to form plastically

5 □ All nonmetals are gases and liquids

6 □ Nonmetals are crucial for the growth and existence of living things on the Earth’s crust

Word Study : Noun Suffixes

Suffixes (word-endings) come at the end of a word They show whether the word is a verb, noun, adjective, or adverb Learning these word-endings can help you recognize a verb, noun, adjective, or adverb

These are common endings for nouns If you see these endings on a word, then you know it must be a noun.

domain, position, rank

a group with position, office, or rank wise+ dom means the state of understanding what is good, right and lasting

king+ dom means the domain or area belonging to a king -ity

capabil ity (n)

flexibil ity( n)

at the end of a word means condition or quality of

capable+ ity means the condition of being capable

flexible+ ity means the quality of being flexible

at the end of a word means state of

tough+ ness means the state of being tough

PART 1 starts with the basics described and ends with a concrete presentation of Latin/Greek

prefixes (tri, tetra, penta, etc) involved in naming binary compounds of nonmetals:

tetraphosphorous nonachloride

PART 2 opens with exercises relating to the names of binary acids, hydro -ic acids and

oxoacids and features 2 pair work activities and a tic-tac-toe style game involving the names

of compounds

UNIT 6

Ionic Bonds & Covalent Bonds

I Read the text carefully and choose the best word for each number to

complete

Oppositely charged ions have (1) strong mutual electrostatic attraction when brought together, but, if brought too close, the electron clouds repel (2) other Thus, a (3) of mutually attracted ions will maintain a certain distance from each other This distance is (4) _the bond length, and the electrostatic (5) _ of the ions constitutes an ionic (or electrovalent) bond Ionic bonds are very (6) _ and are exemplified by table salt, in (7) _ a sodium ion attracts a chloride ion to form

Na+Cl- or, as usually (8) , NaCl Calcium ions (Ca2+) and chloride ions (Cl- ) combine in a one-to-two ratio to (9) _ calcium chloride, CaCl2 The total charge on each combination of ions, NaCl and CaCl2, is (10) , or zero

5 A attracts B attraction C attracting D attractive

6 A a common B common C commonly D in common

II LISTENING Listen to the following text 3 TIMES and fill in the missing

words into the blanks (Blank 5 and 8 should be filled in 2 words)

Predicting a Molecule's Shape

Molecules with a central atom form predictable shapes that depend on the number of electron pairs residing in the outer shell of the central atom The repulsive force between these outer electron pairs causes them to take positions as far from each other as possible The position of the electron pairs in the outer shell then determines the angles at which the central atom bonds with the surrounding atoms in the molecule

Another common type of bond, the (1) bond, results when two atoms share one

or more pairs of electrons in an attempt to fill their outer shells and become more energetically (2) _ The atoms are held together by the mutual electrostatic attraction between the (3) _ in their nuclei and these electrons The bonded atoms form a stable unit called a (4)

For example, because a chlorine atom is one electron short of completing its (5)* (and attaining a noble-gas configuration), two chlorine atoms combine to form a chlorine molecule by sharing two electrons The atoms thereby complete each other’s outer shell: Cl + Cl → Cl2 Electron sharing (6) a covalent bond from an ionic bond

In an ionic compound there are no molecules—only charged (7) _ composing an extensive (8)* _ array

Covalent bonds tend to form when the bonded atoms have nearly the same attraction for electrons; ionic bonds form when the electron-attracting (9) of the atoms differs markedly If the valence electrons are represented by dots, the (10) between bond types becomes more (11) _:

Sometimes two or three pairs of electrons will be (12) _between two atoms, (13) double or triple bonds:

Compounds such as LiF, BeO, and BeF2 are ionic in character, whereas molecules formed between neighbors or near neighbors in the periodic table are more often (14) (such as

CO2, CF4, NO2, N2, O2, and F2) Some metals, however, form both ionic and covalent bonds

A (15) _ rule for remembering whether the bond between two elements is likely to be ionic or covalent is that if one element appears on the left side of the periodic table and the other on the right, the bond is ionic

STOP AND CHECK

Polarity and Electronegativity

II READING COMPREHENSION

TEXT 1

Alignment of Polar Molecules

Between a pure covalent bond (as in Cl2) and a strongly ionic bond (as in LiF), there is a gradual shift from one bond type (1) the other that is related to the differences (2) electron attraction between the bonded atoms The ability of an atom (3) _ electrons in a bond is called its electronegativity—the stronger an atom pulls electrons, the(4) _ its electronegativity Elements on the right side of the periodic table (except for the noble gases) are the most (5) , because they need fewer electrons than elements on the left side to fill their outer shell and attain the stability of a noble gas For example, fluorine

is much more electronegative than potassium

Bonds between atoms of widely different electronegativity are highly ionic, because strongly electronegative atoms (such as oxygen) tend to pull electrons away (6) _ less electronegative atoms Bonds between atoms of more (7) electronegativity take on

a more covalent character and eventually become (8) covalent Since the chlorine atoms in Cl2 have identical electronegativity, this bond is purely covalent, and the atoms exactly share their electrons The bond between hydrogen and oxygen atoms in water is (9) covalent and has some ionic character: the oxygen is more electronegative than the hydrogen and has a (10) _ share of the bonding electrons Such bonds are said to be polar, because the shared electrons are held more tightly by the oxygen atom (giving the oxygen atom a slightly negative charge) and pulled away from the hydrogen atoms (giving the hydrogen atoms a slightly positive charge) Molecules with more ionic bonds are more polar than molecules with less ionic, more covalent bonds

Read the above text and choose the most appropriate word for each space

3 A attracted B attract C to attract D attractive

4 A more highly B highly C higher D more higher

5 A electric B electronegation C electronegativity D electronegative

8 A completely B completion C complete D completed

10 A more greatly B greatly C more great D greater

TEXT 2

Understanding the organization of the text: Choose the appropriate subtiles

of the following list to put in order according to the text

III Introduction

Gold

Chemical properties of gold - Health effects of

gold - Environmental effects of gold

Electronegativity ccording to Pauling 2.4

Energy of second ionisation 1974.6 kJ.mol -1

Gold is usually alloyed in jewellery to give it more strength, and the term carat describes the amount of gold present (24 carats is pure gold) It is estimated that all the gold in the world, so far refined, could be placed in a single cube 60 ft on a side

The most common gold compounds are auric chloride (AuCl3) and chlorauric acid (HAuCl4)

A mixture of one part nitric acid with three of hydrochloric acid is called aqua regia (because

it dissolved gold, the King of Metals) It is unaffected by air and most reagents

B _

Gold is used as buillon and in jewellery, glass and electronics Jewellery consumes around 75% of all gold produced Gold for jewellery can be given a range of hues depending on the metal with which is alloyed (white, red, blue, green etc.) Colloidal gold is added to glass to colour it red or purple, and metallic gold is applied as a thin film on the windows of large building to reflect the heat of the Sun's ray Gold electroplating is used to in the electronic industry to protect their copper components and improve their solderability

C

Glod is widely distributes on the earth at a background level of 0.03 g/1000 kg (0.03 ppm by weight) Its interness and its high density causes it to concentrate in streambeds, either in small flakes or in larger nuggets, from which it may be recovered by panning It is found free

in nature and associated with quartz, pyrite and other minerals

Most gold is mined and comes from gravels and quarts veins or is associated with pyrites deposits Two thirds of the world's supply comes from South Africa, and 2/3 of USA production is from South Dakota and Nevada Other main mining areas are Canada and Russia Gold is found in sea water, but no effective economic process has been designed (yet)

to extract it from this source World production is around 2500 tonnes per year, but reserves are estimated to be ten of thousand of tonnes

D

Effects of exposure: Inhalation: May cause irritation if exposure is prolonged or excessive

Ingestion: No adverse effects expected Skin: May cause irritation and allergic reaction Eye: May cause irritation

Gold is used to cure rheumatoid arthritis, under a treatment called Chrysoteraphy It is

prescribed when treatment with non-steroid antu-infiammatory drugs is failing to give relief

E _

Gold has not been evaluated for its ecotoxicity However, the biodegradation of gold under aerobic conditions is expected to be very poor and there is no evidence to suggest it creates ecological problems when released into the environment Since gold is insoluble, it is believed

to have minimal bioaccumulation and bioavailability characteristics

III LISTENING: Listen to the following recording (3 times) and choose

the correct answer for each question

1 Lead has been widely since _ for application in metal products

A Because foods contains lead

B Because vegetables, seafood softdrinks contain lead

C Because water in corrosion pipes contains lead

D cigarette smoke also contains lead

4 What diseases can lead cause to humans?

A A rise in blood pressure B Brain damage

C Declined fertility of men D All are correct

5 Which of the follwing diseases does the text not mention?

C Behavioural disruptions D A & B are not mentioned

FURTHER READING

PHYSICAL PROPERTIES

Physical properties of a material are those properties that do not depend on the chemical behavior of the material Physical properties include the state of a material (gas, liquid, or solid), melting point, boiling point, crystal structure, and electrical conductivity

A State

The state of a material is determined by the attraction between its atoms or molecules and by the temperature of the material In the solid state, the attraction between the atoms or molecules is so strong that it holds them rigidly in place The energy of vibration of the molecules of a material increases with a rise in temperature As the temperature rises, the molecules eventually acquire enough energy to break away from their fixed positions, and the

solid either melts or transforms directly into gas (a process called sublimation) The material

melts if the molecular attraction remains great enough to hold the molecules together, and the material sublimes to a gas (in which the molecules are free to move randomly) if the attraction

is too small

B Melting Point

The melting point (or freezing point) of a substance is the temperature at which the solid form

of the substance changes to a liquid (or from liquid to solid) The melting point of water is 0°

on the Celsius (centigrade) temperature scale and 32° on the Fahrenheit scale (see Freezing

D Crystal Structure

Solids may be either amorphous or crystalline in their molecular structure In amorphous

solids, the molecules are arranged haphazardly Glass is an example of an amorphous material Like other amorphous materials, glass does not melt at a particular temperature, because the long, randomly intertwined glass molecules cannot easily become disentangled

As a result, glass softens bit by bit as the temperature is raised, eventually becoming liquid Crystalline materials, on the other hand, have a definite orderly array of atoms, ions, or molecules, as would a pyramid of oranges or cannonballs The orderly arrangement of

particles in a crystal is called a crystal lattice Sand, salt, sugar, diamond, and graphite are

examples of common crystalline materials Each crystalline material has a unique melting temperature (provided the material is not chemically changed by the heat before it melts, as happens with sugar)

In an ionic crystal, the strength of mutual attraction of the ions in the crystal is reflected in the high melting point of the crystal Table salt (or sodium chloride, NaCl), for example, melts at 800° C (1472° F) Many ionic compounds, such as sodium chloride, form crystal arrays in which each positive ion is surrounded by negative ions, and each negative ion is surrounded

by positive ions The closely packed arrangement of ions in a crystalline solid, as well as the strong attraction between oppositely charged ions, accounts for the relatively hard, brittle nature of many ionic crystal solids

Covalent crystal structures are networks of bonded atoms with the atoms occurring at the lattice points of the crystal In the crystal lattice of diamond, each carbon atom is covalently bonded to four neighboring carbon atoms, forming a giant three-dimensional network This three-dimensional network that composes diamond forms the hardest-known naturally occurring substance Most covalent crystal structures are very hard and have very high melting points, because covalent bonds throughout the crystal make it essentially one giant molecule Other examples of covalent crystals include silicon carbide (SiC), sand, and quartz (SiO2)

Metallic crystals have unique properties because of the relationship between the positive ions and the electrons of the metal One of the simpler and more widely used models of metallic crystals shows positive ions arranged at the lattice points of the crystal, with electrons moving

freely (as a so-called sea of electrons) among these positive ions Because electrons in metals

do not belong to any single positive ion and can move freely (carrying their electric charge with them), metals are excellent conductors of electricity If an electric potential is applied to the metal, the electrons will move readily toward the positive electrode, creating an electric current (a stream of electrons) The freely moving electrons also make metals good transmitters of heat (metals are cold to the touch because electrons move heat away from skin)

Molecular crystals are compounds in which the molecules are held together in a crystal lattice

by weak intermolecular attractive forces (for more information, see the Solutions and

Solubility section of this article) These crystals do not form a complete network Because of

the weak attractions between the molecules, molecular crystals have low melting temperatures (typically well below room temperature) and are relatively soft Most molecular organic (carbon-containing) and inorganic compounds form molecular crystals Examples include ice (solid H2O), solid sulfur dioxide (SO2), and solid carbon dioxide (CO2)

Inorganic chemists have made significant advances in understanding the minute particles that compose our world These particles, called atoms, make up the elements, which are the building blocks of all the compounds and substances in the world around us Just as the entire English language is constructed from combinations of the 26 letters in the alphabet, all chemical substances are made from combinations of the 112 chemical elements found on the periodic table

Ninety elements are known to occur in nature, and 22 more have been made artificially Elements—which include substances such as oxygen, nitrogen, and sulfur—cannot be broken into more elementary substances by ordinary chemical means The elements are arranged in the periodic table in rows from the lightest element (hydrogen) to the heaviest (ununbium) These rows are split so that elements with similar chemical properties fall in the same columns

The smallest representative unit of an element is an atom (For example, the smallest representative of the element helium (He) is a helium atom.) When atoms come in close contact, they have a sufficiently large attractive force, a chemical bond, or binding link, forms

between them The combination of two or more atoms bonded together is called a molecule

A molecule is the smallest particle of a substance possessing the specific chemical properties

of that substance For example, an atom of oxygen (O) combines with two atoms of hydrogen (H) to form a water molecule (H2O) While molecules of H2O possess the properties of water, individual oxygen and hydrogen atoms do not

Much of chemistry can be described as breaking substances apart and putting chemical components together to form new substances This process is accomplished by breaking chemical bonds between atoms and creating new bonds, a process known as a chemical reaction

Choose the words in the following box to complete these below sentences

study elements atoms attractive hydrocarbons (2) lightest substances compounds bonds molecules properties possession chemical reaction chemical bound

1 Inorganic chemistry does not include the investigation of

2 _ are compounds composed of carbon and hydrogen that are the parent material of all other organic compounds

3 The of organic compounds is called organic chemistry

4 Ninety are known to occur in nature, and 22 more have been made artificially

5 The particles, called _, make up the elements, which are the building blocks

of all the compounds and in the world around us

6 When atoms come in close contact, they have a sufficiently large force, a chemical bond, or binding link, forms between them

7 The elements are arranged in the periodic table in rows from the element (hydrogen) to the heaviest (ununbium)

8 While of H2O possess the properties of water, individual oxygen and

hydrogen atoms do not

9 _ _ is accomplished by breaking chemical bonds between atoms and

creating new bonds

10 A molecule is the smallest particle of a substance possessing the specific chemical

_ of that substance

LISTENING

1 Listen to the folowing text 3 times and fill in the blanks

Inorganic chemistry is the (1) of chemistry concerned with the properties and

behavior of inorganic compounds This field covers all chemical compounds except the myriad organic compounds (compounds containing C-H (2) ), which are the subjects of organic chemistry The (3) between the two disciplines is far from

absolute, and there is much overlap, most (4) in the sub-discipline of organometallic chemistry

Industrial inorganic chemistry

Inorganic chemistry is a highly practical area of (5) Traditionally, the scale of

a nation's economy could be evaluated by their (6) of sulfuric acid The top 20 inorganic chemicals (7) in Canada, China, Europe, (8) , and the

US (2005 data): aluminium sulfate, ammonia, ammonium nitrate, ammonium sulfate, carbon black, chlorine, hydrochloric acid, hydrogen, hydrogen peroxide, nitric acid, nitrogen, oxygen, phosphoric acid, sodium carbonate, sodium chlorate, sodium hydroxide, sodium silicate, sodium sulfate, sulfuric acid, and titanium dioxide,

2 Listen to the recording 3 times and write T (True) or F (False) in the box for the following sentences

1 □ The ions’ease of information can only be inferred from the ionization potential

2 □ The most important class of inorganic compounds is the halidates

3 □ The simplest inorganic reaction is double displacement

4 □ Electron exchange can occur directly

5 □ A reaction can take place by exvhanging protons in acid-base chemistry in evey condition

6 □ It is impossible to find inorganic compounds in natural as minerals

We use both when and while as subordinating conjunctions to introduce adverbial clauses

of time They mean during the time that and indicate that something is or was happening

when something else occurred:

• The prisoners escaped when / while the prison warders were eating their lunch

• When / While the prison warders were eating their lunch, the prisoners escaped

Note that we can also use as and whilst in the same way, although they sometimes sounds more formal or literary