Transcript UNIT 2 CLASSIFICATION

UNIT 1
MATERIALS
Vocabulary
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Names of materials
Characteristics of materials
Adjectives and dimensions
Word formation: SUFFIXES to form ADJECTIVES
Grammar and functions
• Giving definitions & describing
• Articles
• Expressing measurements
NAMES OF MATERIALS
1. Aluminium b Light to carry and silvery to look at.
2. Brass p Mixture of copper and zinc.
3. Bronze o Mixture of copper and tin .
4. Carbon dioxide f Gas produced in the combustion of fossil fuels
5. Chromium l Hard, shiny metal used to coat other metals to prevent rust.
6. Concrete k Building material made by mixing cement and gravel.
7. Copper n Soft, reddish-brown metal, used in wires
8. Gold g Valuable yellow metal which is a very good conductor.
9. Hydrogen j The lightest gas and the simplest element in nature
10. Iron e With symbol Fe, it is the main component of steel.
11. Lead r Soft, grey, heavy metal used in pipes, whose symbol is Pb
12. Mercury d Heavy, silvery metal, usually a liquid at room temperature.
13. Nitrogen m 80% of the air.
14. Oxygen q Colourless and tasteless gas supporting life
15. Tin i A can is made of it and its symbol is Sn
16. Uranium c Heavy, white metal whose atoms can be fissioned
17. Zinc a Hard, bluish-white metal used in alloys and in roofing.
18. Steel h Iron plus carbon.
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
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OXYGEN
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MAGNESIUM
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SILICON
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SULPHUR
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IRON
VIDEO
Process: nuclear fusion
• 2 HYDROGEN atoms= HELIUM +
ENERGY-> SUNLIGHT
• HELIUM + HELIUM = CARBON
• HELIUM + CARBON = OXYGEN
• OXYGEN + HELIUM = MAGNESIUM
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Right up to IRON
• For each of these fusion reactions to
occur, INCREASING TEMPERATURE
and PRESSURE are needed
DESCRIPTIONS
• Silver is a very ductile malleable shiny greyish-white element having the
highest electrical and thermal conductivity of any metal. (0) Silver has
long been valued as a precious metal, and it is used as an investment,
to make (0) jewelry, and (0) currency coins. Today, (0) silver is also
used in (0) electrical contacts and (0) conductors, and for making (0)
mirrors, (0) photographic chemicals, etc.
• Glass is an amorphous inorganic solid; it is a hard, brittle,
noncrystalline, more or less transparent substance produced by (0)
fusion, usually consisting of a mixture of (0) dissolved silicates, as in the
ordinary variety used for (0) window panes and (0) bottles.
• Graphite: a blackish soft allotropic form of (0) carbon, with (0) metallic
luster and (0) greasy feel. It consists of (0) layers of (0) carbon atoms.
Unlike (0) diamond, (0) graphite is an electrical conductor . It is used in
(0) pencils, (0) coatings and (0) electrodes, as a lubricant, as a
moderator in (0) nuclear reactors, and, in a carbon fibre form, as a tough
light material for (0) sporting equipment
LISTENING1: what is a metal?
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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 graphite, 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
ARTICLES
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.... Ø...corrosion is ...a...very serious problem in Ø. metallic
structures.
2. .. Ø..iron is used in ... Ø. engineering due to ...its..... strength.
3. ....the.. physical properties of .... Ø. matter will be studied in Ø
chapter 3.
4. Ø fission is one of ....the.. two types of Ø nuclear reactions which
release Ø large amounts of Ø energy. The fission of Ø Uranium
atoms is used in Ø nuclear power plants to generate Ø electricity.
5. The major component of Ø steel is Ø iron, a metal that in its pure
state is not much harder than Ø copper.
6. Ø silicon is used as a semiconductor in the manufacture of Ø
chips.
7. Ø plastics may be classified into two major groups according to
their chemical composition.
8. Ø mathematics is basic for an engineer.
9. An alloy is a metallic substance composed of two or more
elements as either a compound or a solution.
10. In Ø Kevlar, an artificial fiber, the molecules lie straight, giving it
Ø/its 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 poor conductor of Ø
heat and a fair conductor of Ø electricity.
Ø mercury is the only common metal that is a liquid at Ø
ordinary temperatures.
It easily forms Ø alloys with many other metals.
When it combines with certain metals (such as Ø silver, Ø
zinc or Ø tin), the resulting alloy is called an amalgam.
Both the element and Ø most of its compounds are
poisonous.
Ø mercury and its compounds are used in Ø electrolytic
cells, Ø dentistry, Ø thermometers, Ø batteries, and in Ø
medicine.
DESCRIBING
• Definition:
• Composition:
X is
It is made (up) of
It consists of
It has
It is composed of
It is formed by
GENERAL CLASS
Materials
Substances
Components
Parts
Pieces
• Characteristics: WHAT IS IT LIKE?
To be
To look
To seem
To become
To have
+ ADJ
+ ADJ
+ADJ
+ ADJ
Shape (circular, elliptical)
Properties (flexible, tough)
Colour (blue, greenish)
Texture (hard, smooth)
Temperature (warm, cold)
Dimensions (long, thin, small)
+ NOUN
• 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, curved
COMPOSITION: metallic, plastic, ferrous, synthetic,
organic, golden
SIZE: huge, tiny, minute, large, broad, short
COLOUR: light, bright, dark, opaque, reddish, golden
WORD FORMATION: Adjectives
ADJECTIVES FROM NOUNS
LATIN ORIGIN OR ROOT
ENGLISH ORIGIN
-IC
atomic
-FUL beautiful
-AL/AR usual/linear
-LESS harmless
-OUS poisonous/ lustrous -(L)Ysunny
-IVE
destructive
-ISH yellowish
-ENT/-ANT different/important
ADJECTIVES FROM VERBS
-ING boring
-ED concentrated
IBLE/ -ABLE responsible/drinkable
WORD FORMATION
STAINLESS STEELS
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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
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The Ballwell meteorite fell in 1965.
BROWN METALLIC skin due to ATMOSPHERIC HEATING
it consists of : SILICATES....... (..GREEN....olivine)
some..METAL (BROWN DISCOLORATION DUE TO OXIDATION OF
IRON)
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.
MEASUREMENTS
• X is 3 m +ADJ
(eg: The bar is 3m LONG)
• X is 3m + IN + NOUN
(eg:the bar is 3m IN LENGTH)
• X has a +NOUN + OF 3m
(eg: the bar has A LENGTH OF 3m)
• The NOUN + OF X is 3m
(eg: THE LENGTH OF the bar is 3m)
What is it like?
HOW + ADJ /WHAT + NOUN Is this object?
(eg: HOW LONG / WHAT SHAPE is the
component? It is 3m long / rectangular
1.
EXERCISE:
Measurements
The film coating the piece must be very THIN. It should be
0.05 mm THICK
2. The light travels along THE LENGTH of the optical fibre
3. How HIGH is the new tower? It is 10ft HIGH
4. 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
5. The beams needed for the structure must be 3 m LONG and
25 cm THICK/WIDE
6. To take the recordings, the thermometer was placed at a
HEIGHT of 1.5 m above ground level.
7. The piece of the machine is too long to fit in the slot, so we
must make it SHORTER
8. 3-D objects have three main dimensions: HEIGHT, WIDTH
and LENGTH
9. The reaction produces a layer on top of the solution, with
THICKNESSES ranging from 0.2 to 0.6 mm
10. WHAT IS THE PIECE LIKE? /WHAT SHAPE is it?. Well, it is
cylindrical
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 – 1.05cm top
• it weights 782 kg
PERFORMANCE:
• 1700 hours
• 350 rpu (revolutions per unit)