UNIT 2 CLASSIFICATION Vocabulary Materials countable vs uncountable

UNIT 2 CLASSIFICATION Vocabulary • Materials: countable vs uncountable nouns (i. e. general vs specific) • Revision of names of materials • (WORD FORMATION: NOUNS from VB) Grammar and functions • Expressing classification • AS, HOW and LIKE • Introduction to connectors

CLASSIFICATION OF MATERIALS • • • ACCORDING TO THE STATE OF MATTER SOLIDS, e. g. COPPER GASES, e. g. CARBON DIOXIDE DIVIDE MATERIALS INTO METALS AND NONMETALS DEPENDING ON WHETHER THEY ARE PURE METALS ALLOYS, e. g BRONZE METALS CAN BE CLASSIFIED INTO IRON AND ALL OF ITS ALLOYS LEAD, GOLD OR MERCURY

CLASSIFICATION OF MATERIALS • • • • CERAMICS, PLASTICS, COMPOSITES, RUBBER PLASTICS, …, CAN BE DIVIDED INTO THEIR MOLECULAR STRUCTURE CHANGES AS MANY TIMES AS NEEDED ELECTRICAL CONDUCTIVITY CONDUCTORS, INSULATORS AND SEMICONDUCTORS THEY PERMIT AN ELECTRIC CURRENT TO FLOW MOST METALS LIKE CARBON OR SALT WATER PLASTICS AND CERAMICS ARE INSULATORS SILICON ACT AS CONDUCTORS OR INSULATORS IN MANY DIFFERENT WAYS

CLASSIFYING GENERAL CLASS is/are may be can be could be Includes Contains consists of is made up of is formed by is composed of comprises classified divided grouped arranged categorized classified categorized classed grouped into divisions groups types classes categories as solids, liquids or gases

CLASSIFYING SPECIFIC ITEM is classed classified categorized is put into falls into belongs to is as GENERAL CLASS the class / category of GENERAL CLASS an example (type, kind, form. . ) of GENERAL CLASS IN many / different / various WAYS

CLASSIFYING Basis of the classification according to on the basis of based on depending on criteria characteristics the following features properties whether (+ CLAUSE)

COMPLETE THE TABLE Engineering materials metals ferrous

COMPLETE THE TABLE Engineering materials non-metals non-ferrous lead gold ferrous ceramics plastics mercury thermosets iron alloys thermoplastics

HOW / AS / LIKE HOW • CÓMO (indirect question) (e. g. He told me how to do it) • LO + ADJ/ADV (e. g. Tell me how fast the car runs) LIKE • Adjective = IGUAL o SEMEJANTE (opposite : “unlike”) (e. g. Like poles repel and unlike poles attract) • COMO = PARECIDO A, IGUAL (QUE) (if with vb = -ING) (e. g. A computer is like a typewriter) Plastics are composed of long chain-like molecules called polymers • COMO = POR EJEMPLO (e. g. ) Some metals, like steel or brass, are alloys Expressions • TO BE LIKE = SER COMO (e. g. What is it like? ) • TO LOOK LIKE = SER PARECIDO A (e. g. This object looks like a square box)

AS AS as a PARTICLE • Comparative : “as. . . as” (e. g. Thermoplastics can be heated as many times as required) • In co-relation with THE SAME : “the same as” (e. g. Rubber has the same properties as plastics) • EN CALIDAD DE / COMO (e. g. Oil is used as a fuel) AS + SENTENCE (Subject + Vb) • COMO : (e. g. As I was saying, magnetic fields cannot be seen) • A MEDIDA QUE: (e. g. Steel becomes hard as it cools down) • PUESTO QUE: Copper is widely used in wires as it is ductile Expressions • AS IF / AS THOUGH = COMO SI (+ subjunctive) • SO AS TO = CON OBJETO DE, PARA (+ infinitive) • AS FAR AS = EN CUANTO A , CON RESPECTO A

EXERCISE 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. AS expected, the lecture began 2 hours late. I am going to explain HOW electrolysis can be used AS a process to coat objects with thin films of metals LIKE/SUCH AS chromium or gold. Electroplating is LIKE painting an object but covering it with a metal. We can observe HOW the needle moves AS we place the compass near a coil. A piece of iron can be used AS a magnet when it is magnetized. Thermosets break down AS their temperature rises. Some metals, LIKE/SUCH AS aluminium and copper, are pure metals. I have never used a device LIKE this one before. Semiconductors act AS conductors under certain conditions but AS insulators under others. Electrons are attracted by positively charged particles AS they have a negative electric charge. The boiler of a power plant works LIKE a big kettle. Some new materials behave LIKE both solids and liquids. AS tin is fairly weak, it is not used in structures. Computers may change the order of some instructions SO AS TO improve performance

CONNECTORS 1. Copper is a good conductor, THEREFORE/THUS it is used in wires. 2. Cast iron is not used to withstand impact loads BECAUSE/AS/SINCE it is a brittle material. 3. Titanium is used for aircraft frames BECAUSE/AS/SINCE it is light and strong. 4. Chromium resists corrosion THEREFORE it is added to steels to make them rust proof. 5. Aluminium and iron are pure metals WHEREAS/WHILE bronze and steel are alloys 6. Stainless steels have a high strength. HOWEVER, they are expensive and difficult to machine. 7. Tin is used to coat other materials to protect them BECAUSE/AS/SINCE it resists corrosion 8. Tin is expensive; THUS/THEREFORE the coats of tin are very thin. 9. Nickel & chromium improve the properties of metals; THEREFORE /AS A RESULT they are added to steel 10. Alloys, i. e. / THAT IS mixtures of materials, ….

WORD FORMATION NOUN from VERB -ing -> English (e. g. building) -tion/sion ->Latin (e. g. Explanation/emission) -ment (e. g. management) - er/or (object) (e. g. boiler/conductor) - ure (e. g. mixture) - ent/ant (e. g. content/coolant) - nce (e. g. performance) - age (e. g. drainage) - al (e. g. disposal) - y (e. g. discovery)

WORD FORMATION 1. EXPOSURE to GASEOUS fluorine. 2. IMPROVEMENTS … RESISTANCE …FULLY … PITTING 3. DENSITY … its SUBSTITUTION …. WEIGHT …HARMFUL … EMISSIONS 4. its STRENGTH … its ABILITY … DEFORMATION …its RESISTANCE … to DEFLECTION 5. COMPONENTS … CHEMICALLY …. ENVIRONMENTALLY safer COOLANTS … higher PRESSURES

WORD FORMATION: Aluminium • • • • ACTIVITY ENGINEERING DEVELOPMENT APPLICATIONS TOUGHNESS or DUCTILITY FAILURE. ACCEPTANCE COMPONENTS REFRIGERANTS or COOLANTS and PRESSURES WORKABILITY and corrosion RESISTANCE ABILITY STRENGTH TREATMENT

GRAMMAR REVISION There are MANY (muchos) types of STEEL (acero) DEPENDING ON/ON THE BASIS OF/ACCORDING TO (según) the materials added to it. For example, steel that contains VERY LITTLE (muy poco) CARBON (carbono) is known AS (como) low carbon steel, and it is very malleable. HOWEVER (Sin embargo) steel with a higher carbon content becomes LESS (menos) malleable, AS (ya que) carbon makes it harder and THEREFORE (por lo tanto) more difficult TO MOULD/SHAPE (de moldear), but ON THE OTHER HAND (por otra parte) it can resist higher loads. Other types of STEEL (acero) include some other materials, LIKE/SUCH AS (como) chromium to make STAINLESS STEEL (acero inoxidable). THUS (Así pues), we can classify steel INTO (en) different groups ACCORDING TO (según) the properties that we require and HOW (cómo) the steel is manufactured.

THE PERIODIC TABLE • First classification: METALS, SEMIMETALS, NON METALS • USES • Non-metals: Most are GASES Examples: OXYGEN and NITROGEN in THE AIR • Used in balloons because they are LIGHT GASES • Low liquefaction point: HELIUM & HYDROGEN uses PRODUCTION OF LOW TEMPERATURES (e. g. SUPERCONDUCTING MAGNETS and REFRIGERATION PURPOSES • Reactive gases: e. g. CHLORINE and FLUORINE. Reactions are sometimes a nuisance because they produce CORROSION • Inert gases: eg ARGON Uses in INDUSTRY because OF THE OPPOSITE REASON (THEY DO NOT CORRODE) • For example, it is used to create an inert atmosphere for THE PRODUCTION OF SPECIAL PLASTICS • Argon is the cheapest INERT GASES • Normal atmosphere produces OXIDATION-> critical degradation of the material -> important if the plastic is to be used for OPTICAL TRANSMISSION PURPOSES

VIDEO • Not all non-metals are gases: • CARBON: Diamond structure -> natural-> uses JEWELLERY and ornament. Characteristic: HARDNESS; Use in industry CUTTING VERY HARD MATERIALS • GRAPHITE : characteristic VERY SOFT eg. lead pencils • another property: CARBON ALSO CONDUCTS ELECTRICITY eg. dry cell -> • CARBON is used as one of the ELECTRODES • Another example: in commercial electrolytic cells USE OF GRAPHITE