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

2. CLASSIFICATION OF MATERIALS ACCORDING TO THE STATE OF MATTER SOLIDS, e.g. COPPER GASES, e.g. CARBON DIOXIDE DIVIDE MATERIALS INTO METALS AND NON- METALS 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

3. 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

4. CLASSIFYING GENERAL CLASS classifieddivisions dividedgroups groupedintotypes is/arearrangedclasses may becategorizedcategories can be could beclassified categorized classedassolids, liquids or gases grouped Includes Contains consists of is made up of is formed by is composed of comprises

5. CLASSIFYING SPECIFIC ITEM classed isclassifiedasGENERAL CLASS categorized is put into falls intothe class / category ofGENERAL CLASS belongs to isan example (type, kind, form....) of GENERAL CLASS INmany / different / various WAYS

6. CLASSIFYING Basis of the classification criteria according tocharacteristics on the basis of the following features depending onproperties whether (+ CLAUSE)

7. COMPLETE THE TABLE Engineering materials non-ferrous lead thermoplastics plastics non-metals metals ferrous ceramics goldmercury ironiron alloys thermosets

8. 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) (e.g. A computer is like a typewriter) COMO POR EJEMPLO (e.g.) (e.g. Some metals, like steel or brass, are alloys) Expressions TO BE LIKE (e.g. What is it like?) TO LOOK LIKE = SER PARECIDO A (e.g. This object looks like a square box)

9. AS Comparative : “as... as” (e.g. Thermoplastics can be heated as many times as required) In co-relation with 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) COMO + independent clause (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 (e.g. Copper is widely used in wires as it is ductile and malleable) 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

10. EXERCISE 1.AS expected, the lecture began 2 hours late. 2.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. 3.Electroplating is LIKE painting an object but covering it with a metal. 4.We can observe HOW the needle moves AS we place the compass near a coil. 5.A piece of iron can be used AS a magnet when it is magnetized. 6.Thermosets break down AS their temperature rises. 7.Some metals, LIKE/SUCH AS aluminium and copper, are pure metals. 8.I have never used a device LIKE this one before. 9.Semiconductors act AS conductors under certain conditions but AS insulators under others. 10.Electrons are attracted by positively charged particles AS they have a negative electric charge. 11.The boiler of a power plant works LIKE a big kettle. 12.I would like to work AS an engineer for your company. 13.We can mention steel AS an example of an alloy. 14.A piece of iron is placed inside the coil SO AS TO increase the magnetic properties of the metal

11. 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.

12. 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,….

13. ESSAY 1 (Units 1-2) In about 150 words write different CLASSIFICATIONS for the materials of the book (p30) and DESCRIBE some of them. USE STRUCTURES OF UNITS 1 (p 13) & 2 (p 27) INCLUDE and UNDERLINE: - BASIS OF CLASSIFICATION (p 27) - THE EXPRESSIONS AS, HOW & LIKE (p28) -AT LEAST 3 CONNECTORS -STRUCTURES of DESCRIPTION (p13) & CLASSIFICATION -5 ADJECTIVES FORMED WITH A SUFFIX (p 17) DEADLINE: 13 th MARCH (essays will only be accepted within given timelines)