UNIT 1

MATERIALS

• • • •

Vocabulary

Names of materials Characteristics of materials Adjectives and dimensions Word formation: SUFFIXES to form ADJECTIVES

• • •

Grammar and functions

Giving definitions & describing Articles Expressing measurements

VIDEO

SECTION 1 : elements found in all stars.

Profile of the abundance of elements found in stars:

-immense amounts of

HYDROGEN

and

HELIUM

.

• • • • •

-

LOWER

amounts (

2

%) of the heavier elements • Peaks

CARBON OXYGEN MAGNESIUM SILICON SULPHUR IRON

VIDEO

• • • • •

Process: nuclear fusion 2 HYDROGEN atoms= ENERGY -> SUNLIGHT HELIUM + HELIUM + HELIUM HELIUM + CARBON OXYGEN + HELIUM Right up to IRON = CARBON = = OXYGEN MAGNESIUM

•

For each of these fusion reactions to occur, INCREASING TEMPERATURE and PRESSURE are needed

• • • • •

DESCRIPTIONS

Graphite

: a blackish soft allotropic form of (0) carbon, with (0) metallic luster and (0) greasy feel. It consists of layers of carbon atoms. Unlike (0) diamond, (0) (0) graphite is coatings and (0) electrodes, as a nuclear reactors, and, in an a electrical conductor . It is carbon fibre form, material for (0) sporting equipment lubricant, as as a a used in (0) moderator in pencils, (0) tough lightweight

Ceramics

: A ceramic material may be defined as an oxide material. It is solid and inert. (0) inorganic crystalline Ceramic materials are brittle, hard, strong in (0) compression, weak in (0) withstand (0) very high temperatures tension. (0) Ceramics can generally

Nylon

is a thermoplastic, silky material made of repeated units of amide bonds. It is very strong and elastic. It is used to make (0) fabrics, (0) ropes , (0) musical strings, and for (0) mechanical machine components

Petrol

is

a

volatile flammable liquid. It consists of hydrocarbons. It is used as

a

fuel especially in (0) (0) short-chain internal combustion engines and as a solvent

Plastics:

(0)

a

plastic substance is any of the processed materials polymers of (0) consisting of high molecular numerous organic synthetic or (0) very large molecules that are mostly

weight

and can be made into (0) objects, (0) films, or (0) filaments

• • • • • • • • • • • • • •

LISTENING: what is a metal?

We are so familiar with metals that it might be quite a surprise to be asked the question: What is a metal?. Take magnesium for example. It burns easily . Why then do we regard magnesium as a metal similar to say iron which will not burn ?

The most important properties that distinguish metals from non-metals are: they reflect light and thus are shiny They are good conductors of heat and electricity They combine with fluorine and chlorine Most react with acids and with oxygen Apart from these similarities, metals show a great deal of variation. Gold, lead and sodium are very soft materials, much softer for example than silicon and graph ite, both non-metals. Many metals corrode easily . Gold, chromium and platinum , however, do not. Some metals are very active: sodium, calcium and potassium combine easily with oxygen, chlorine and fluorine . Gold, silver and mercury , on the other hand, do not form compounds so easily.

Metals far outnumber non-metals: only 20 of the 103 elements known today are non-metallic

1.

2.

3.

4.

5.

6.

ARTICLES (1)

...Ø...

petrol is used as engines.

..a.

fuel in .. Ø..

combustion .... Ø...

corrosion is ...a...

very serious problem in Ø.

metallic structures.

.. Ø..

iron is used in ... Ø. engineering due to ...its..... strength.

....the.. physical properties of .... Ø.

studied in Ø chapter 3.

matter will be There are many energy sources, like ...Ø...

...Ø...

coal oil or Ø fission is one of ....the..

reactions which release Ø two types of Ø nuclear large amounts of Ø energy. The fission of Ø Uranium atoms is used in Ø nuclear power plants to generate Ø electricity.

ARTICLES (2)

7. The/a major component of Ø steel is Ø iron, a metal that in its pure state is not much harder than Ø copper.

8. A generator is a machine which produces Ø electricity 9. Ø silicon is used as a manufacture of Ø semiconductor in chips.

the 10. Ø plastics may be classified into two major groups according to their chemical composition.

11. Ø mathematics is basic for an engineer.

12. An alloy is a metallic substance composed of two or more elements as either a compound or a solution.

13. In Ø Kevlar, an artificial fiber, straight, giving it Ø/its the molecules lie strength and Ø/its stiffness

ARTICLES: MERCURY

Ø mercury is a/the chemical element whose symbol is Hg.

It is a silvery-white, heavy, liquid metal. Compared with other metals, it is a heat and a fair conductor of Ø poor conductor of electricity. Ø Ø mercury is the only common metal that is ordinary temperatures. a liquid at Ø It easily forms Ø alloys with many other metals. When it combines with certain metals (such as Ø zinc or Ø tin), the resulting alloy is called an silver, Ø amalgam. Both the element and Ø poisonous. most of its compounds are Ø mercury and its compounds are used in Ø cells, Ø dentistry, Ø thermometers, Ø electrolytic batteries, and in Ø medicine.

DESCRIBING

• • • •

Definition

:

Composition

: It is made (up) of It consists of It has It is composed of It is formed by X is GENERAL CLASS Materials Substances Components Parts Pieces

Characteristics:

To be To look To seem To become + ADJ + ADJ +ADJ + ADJ Shape (circular, elliptical) Properties (flexible, tough) Colour (blue, greenish) Texture (hard, smooth) + NOUN Temperature (warm, cold) Dimensions (long, thin, small) To have

Applications:

X is used for (+GER) / to (+INF) X is used in/as (+NOUN) X serves to (+INF)

VOCABULARY: Adjectives

TEMPERATURE: Boiling, Molten, Cool, warm, Burning, Icy TEXTURE: rough, hard, smooth, soft, sticky SHAPE: rectangular, straight, cylindrical, square, rounded, sharp COMPOSITION: metallic, wooden, plastic, ferrous, synthetic, organic SIZE: huge, tiny, minute, large, broad, short COLOUR: light, bright, dark, opaque, faded, reddish

WORD FORMATION: Adjectives

ADJECTIVES FROM NOUNS LATIN ORIGIN OR ROOT

-IC atomic -AL/AR usual/linear -OUS poisonous/ lustrous

ENGLISH ORIGIN

-FUL beautiful -LESS harmless -(L)Y sunny -ISH yellowish

ADJECTIVES FROM VERBS

-ING shining -ED concentrated -IVE

ADJECTIVES FROM VERBS OR NOUNS (usually from a Latin origin)

-IBLE/ -ABLE -ENT / -ANT terrible/drinkable different/important massive

WORD FORMATION

STAINLESS STEELS

•

StainLESS

steels contain chromium, nickel • and other

alloyING

elements • that keep them rust

resistANT

• in spite of the action of moisture or

corrosIVE

acids and gases. • Some steels have

unusUAL

strength.

• Because of their

shinY

surfaces • architects

wideLY

use them • for

decoratIVE

purposes

.

• • • • • • • • • • • • • • • • •

VIDEO: METEORITES

The Ballwell meteorite fell in 19

65

.

BROWN METALLIC

skin due to

ATMOSPHERIC HEATING

it consists of :

SILICATES

....... (..

GREEN

....olivine) some..

IRON

)

METAL

(

BROWN DISCOLORATION DUE TO OXIDATION OF

chondrules Section of a chondritic meteorite: chondrules

SILICATES

.....(

OLIVINE

........)

DARK

............patches(

IRON METAL

.........) Iron meteorites: Blades

OF IRON-NICKEL ALLOY (IRON WITH A LITTLE NICKEL ) INCLUSIONS OF IRON SULFIDE

......

Meteorites contain three principal phases: 1-

OLIVINE (MAGNESIUM SILICATES

) 2-

IRON OFTEN WITH A LITTLE NICKEL

3-

IRON SULFIDE

...........

Chondritic meteorites appear to have changed chemically the least since their condensation from the primitive solar nebula. They contain

HYDROGEN

and

HELIUM

but otherwise their element abundance should be similar to the abundance in the solar spectrum.

LISTENING: Temperatures

• The most commonly used metal in industry is

IRON

. Its symbol is

Fe

, its atomic weight

55.19

and its specific weight is

7.86 GR/CM3

. Its melting point is

1,528ºC

; this is a metal which is magnetized quite strongly but above

768ºC

it cannot be magnetized.

• Another metal of a great importance in engineering is

ALUMINIUM

, with an atomic weight of

26.97

, a specific weight of

2.7 GR/CM3

and its melting point is

658ºC

• Among metals,

LEAD

is the metal which possesses the highest density, with an atomic weight of

207.22

and a specific weight of

11.34 GR

/

CM3

; contrarily to other metals, however, its melting point is relatively low as it melts at

327ºC

.

LISTENING: Temperatures

• However not all metals have the same characteristics; as an example we have

MERCURY

which is

A LIQUID

at room temperature; thus, the temperature at which this metal changes from liquid to solid is

–38.9ºC

and its boiling point is

357.2ºC

.

• Non-metals, on the other hand, vary greatly with regard to their characteristics. For example,

CHLORINE

has a specific weight of

0.0032 GR/CM3

and its boiling point is

–33.7ºC

. However,

SILICON

, whose specific weight is

2.33

, melts at

1,310ºC

and boils at

2,355ºC

.

•

DESCRIBING

Dimensions:

–

General dimensions

(thin, long, small) –

Specific dimensions

X is 3m+ADJ (long) X is 3m+IN+NOUN (in length) X has a +NOUN + OF 3m ( ´X has a length of 3m) The NOUN+OF X is 3m (The length of X is 3m)

1.

2.

3.

4.

5.

6.

7.

EXERCISE: Measurements

The film coating the piece must be very

THIN

. It should be 0.05 mm

THICK

The light travels along

THE LENGTH

of the optical fibre In this part of the swimming pool you can dive in because it is 5 ft

DEEP

to the bottom The engineers have built a new tower which is 50 m

HIGH

To make chips, a single crystal in the shape of a long bar of about 10 cm

IN

diameter is cut into circular slices 1/2 mm

THICK

The beams needed for the structure must be 3 m

LONG

and 25 cm

THICK/WIDE

To take the recordings, the thermometer was placed at a

HEIGHT

of 1.5 m above ground level.

8.

9.

EXERCISE: Measurements

The steel bar can resist up to 305 kg IN WEIGHT before breaking The piece of the machine is too long to fit in the slot, so we must make it SHORTER 10. 3-D objects have three main dimensions: HEIGHT , WIDTH and LENGTH 11. The WIDTH of the tunnel decreases as it goes through the mountain, leaving only one lane.

12. The reaction produces a layer on top of the solution, with THICKNESSES ranging from 0.2 to 0.6 mm 13. Pitting is a corrosion process that creates holes of about 0.03 mm DEEP/WIDTH on the surface of the metal 14. HOW WIDE/WHAT WIDTH Well, it is 1/2 m WIDE is the base of the column?.

LISTENING: Dimensions

• •

CHARACTERISTICS OF THE ALLOY

:

Stands very high and very low temperatures melting point = 3,527ºC , below 58ºC

• • • •

DIMENSIONS

:

2.35m high , width =37 cm 1.55m length of its base – it weights 782 kg 1.05cm top

• •

PERFORMANCE

:

1700 hours 350 rpu (revolutions per unit)