Properties of Matter Complete the following texts: 1. Changes of state / form Clue: Below boiling except fluids highly liquid solid state 0°C - melting point of ice. 100°C - __________ point of water. Ice is ________, water is _________, steam is gaseous. Steam and water are ________ . Steam, water, ice, oxygen, neon: all these are fluids _________ ice. Sometimes the properties of a substance change when it changes its __________. For example, if the temperature of oxygen falls ________ -183°C, it changes from a colorless gas to a bluish liquid, which is __________ magnetic. 2. A substance may be an element, a compound or a mixture. Clue: dissolve element form gas hand properties salt salty substance An element, such as copper or iron cannot be broken down into simpler substances. When elements combine to form compounds, there is a chemical reaction. Some ____________ of the elements change during the reaction. For example, the ________ chlorine (Cl) is a poisonous yellow _____. Sodium, on the other ______, is a soft silvery-white metal which reacts violently with water. However, if these elements combine, they ______ sodium chloride, or _____ . This is a harmless white ____________. A mixture of a sand and salt is yellowish-white and it tastes both _____ and gritty. If we put the mixture in water, the salt will dissolve, because it is soluble, but the sand will not _________, because it is insoluble. 3. Properties of matter A breakable material is brittle, or fragile; but if it does not break easily, it is tough [a]. A hard material is difficult to scratch, whereas a soft material is easy to scratch. A flexible material bends easily, e.g. rubber, while a rigid material does not bend easily. Some materials produce little friction when they are rubbed - they have smooth surface. Some materials have a rough [a] surface and produce a lot of friction; e.g. sandpaper. The sea is calm or rough. You can see through [θru:] transparent,materials such as water. You cannot see through translucent materials, such as dirty water, but light passes through them. You cannot see through opaque [əu´peik] glass or other materials and the light cannot pass throughthem. Combustible materials, such as wood burn easily. If gasses burn easily, they are [in´flæməbl] (in)flammable. Some people also have an inflammable temper. Phosphorus is self-ignitable in the light. 4. Word formation: Form the nouns. Hard________, soft_____ , rigid_____, flexible - flexib_______, dissolve - sol_______, Combust________ / combust_______, (in)flame - inflamm_________ / inflamm_______ , ignite - ignit________/ ignit_______. 5. Answer these questions: 1. What is the boiling point of oxygen? 2. Are sodium and chlorine harmless? 3. What is the difference between a compound and a mixture? Adapted from Bates, Martin and Dudley-Evans, Tony: Nucleus of General Science. Longman 1990. Věra Hranáčová, 2011 6. Discuss these questions: a) What is your favourite material for clothing? Do you prefer natural or synthetic materials? Why? What material are you wearing right now? b) Do you know some modern hi-tech materials? (e.g. Gore-tex)? Which ones? Where are they used? What are their advantages over traditional materials? c) Give examples of things which were originally made of natural materials and now are made of plastics. Why are plastics now used? Are there any disadvantages? c) What materials can you see in this classroom? What objects are made of them? d) What material is your watch / pen / book / shoes / computer / mobile phone / bottle made of? e) What are some traditional and modern building materials? Give examples. 7. Some other properties of materials. Form adjectives or nouns. Czech translation Noun Adjective a) pružnost elasticity elastic b) křehkost (nepružnost) brittleness (rocks, bones, glass) c) tažnost, kujnost malleability, ductility d) plastičnost, tvárnost ductility e) vodivost conductivity f) žáruvzdornost heat-resistance g) zápalnost, hořlavost (in)flammability, combustibility x! h) zápalnost ignitability [ig´naitə´biliti] i) jedovatost, toxicita toxic j) reaktivita reactivity k) netečnost inertness l) lehkost light m) těžkost ! heavy n) savost, absorpčnost absorbency o) viskozita, lepkavost viscosity ! p) hustota density q) trvanlivost, odolnost durability r) odolnost proti korozi corrosion resistance s) síla ! strong t) křehkost (ztráta síly) fragility (bones, glass) 8. Choose the right word in a sentence: a) A conductive / conductivity material can be used to conduct electricity. b) If a material is easy to stretch under stress, we call it elastic / elasticity. c) If you want to improve durable / durability of a machine, clean it regularly. d) Hard / hardness is an important property of steel. e) Concrete is used for building because of its strong / strength. Adapted from A. Rozkošná- Bates, Martin and Dudley-Evans,Tony: Nucleus of General Science. Longman 1990. HOMEWORK^ : Science and Technology: Fill in the gap with the correct word. …………….. are being carried out to find a cure for cancer. Experiences Experiments Trials Research Microscopes ………………..very small objects many times to make them visible. magnify enlarge expand increase Radio signals are now often ……………..by satellite. received delivered transmitted dispersed Computers are able to ………………… vast amounts of data very quickly. process digest convert adapt Solar power stations are able to ……………….. the energy of the sun. harm maximise drive harness Other …………… energy sources include wind and wave power. renewable recyclable returnable reusable In some types of power station steam is used to ………………turbines. force turn drive rotate Mercury is a …………….at room temperature fluid liquid solid gas Hydrogen and oxygen are the two ……………….. that make up water. compounds atoms molecules elements All …………..is composed of atoms. stuff material substance matter The ……………… of lead is greater than that of aluminium. rigidity weight density volume When water is heated it …………………..more quickly. evaporates condenses melts solidifies The ………………….. of iron and oxygen produces rust. reaction separation decomposition composition Chemists study the composition of natural ……………….. substances machines mixtures alloys The ………………………….. of water is 100°C. melting point boiling point point of condensation freezing point J.Harbord: Topic-based Vocabulary.