6. PERIODIC TABLE OF THE ELEMENTS Introduction. In one minute try to write down as many elements in English as you can. Video: Periodic Table http://www.youtube.com/watch?v=_6WfnhwyyCw In pairs, check the meaning and pronunciation of these expressions: unique share chart derive refer to behaviour major occur nucleus protons neutrons electrons A) Before watching the first part of the video (5.45 – 7.07) complete these phrases: 1. atoms ……………… of three basic parts 2. positively ……………. protons 3. protons and neutrons form …………….. 4. electrons are separated into ……………. 5. …………… electrons are involved in transfer and sharing with other elements · Watch the part and check your phrases. · Describe the atom without looking at the phrases. B) · What are these elements called – K, H, O? · Z A X What do these symbols mean? Complete the definitions: atomic number – refers to the number of … atomic mass – is determined by … isotopes – are atoms of the same element that have … atomic mass unit – is equal to … Watch the second part and check the diagram and the definitions above. 7.10–10.05 C) Complete the chart with a few examples of properties and 3 names of elements in each group. 18.40 – 20.20 Then listen and compare. ALKALI METALS ALKALINE EARTH METALS OTHER METALS METALLOIDS NON-METALS HALOGENS NOBLE GASES 4. Find the following chemical elements, there are 15 of them. If you cross all of them, the remaining letters, if read from left to right, form a word. Which word is it? A B C D E F G H I 1 C A R B O N I T E 2 A L U M I N I U M 3 L E B S L E M M E 4 C K I N O E N N T 5 I C D R R D A E L 6 U I I C O Z I N C 7 M N U R A N I U M 8 S R M O S M I U M 9 Y T T E R B I U M /´æl thinsp yə’mɪn thinsp i thinsp əm/ /’ɒz thinsp mi thinsp əm/ /’mɜr thinsp kyə thinsp ri/ /’kæl thinsp si thinsp əm/ /ru’bɪd thinsp i thinsp əm/ /’ni thinsp ɒn/ /’kɑr thinsp bən/ /’soʊ thinsp di thinsp əm/ /ɪ’tɜr thinsp bi thinsp əm/ /’aɪ thinsp ərn/ /tɪn/ /’nɪk thinsp əl/ /lɛd/ /yʊ’reɪ thinsp ni thinsp əm/ /zɪŋk/ http://dictionary.reference.com/help/luna/IPA_pron_key.html 5. Speaking. Work in small groups. Try to answer these questions: a) Which element makes more than 90 % of the universe? b) What elements are present in the air? Do you know the percentages? c) Which element is used as rocket fuel and as alternative fuel for cars? d) What elements are present in the human body? e) What are the three forms of carbon? What are their uses? f) What is an isotope? Do you know any isotopes? Which ones? g) Do you know any alloys (combinations of metals)? Which ones? What metals are they made of? h) Which elements can be dangerous? How are they dangerous? 5. What do you know about arsenic? Listening / Watching. ARSENIC. Watch the video and note down the uses of arsenic.^1 Vocabulary: sample (n) - vzorek dispose of (v+prep) – zbavit se mould (n) – plíseň feed livestock (v) – krmit dobytek volatile (adj) – těkavý powder (n) – prášek damp (adj) – vlhký poisonous (adj) - jedovatý vial (n) - lahvička Uses of arsenic: 6. Reading: ARSENIC.^ After you have read the text complete the table with suitable information. ARSENIC^2 Arsenic is the chemical element that has the symbol As, atomic number 33 and atomic mass 74.92. Arsenic was first documented by Albertus Magnus in 1250. The element is a steel grey, very brittle, crystalline solid. Arsenic is a poisonous element that occurs in the earth’s crust. It is metalloid with many allotropic forms, including a yellow (molecular non-metallic) and several black and grey forms (metalloids). Three metalloidal forms of arsenic, each with a different crystal structure, are found free in nature. In the environment, arsenic is combined with oxygen, chlorine, and sulfur to form inorganic arsenic compounds. Arsenic in animals and plants combines with carbon and hydrogen to form organic arsenic compounds. The most common oxidation states for arsenic are −3 (arsenides: usually alloy-like intermetallic compounds), +3 (arsenates(III) or arsenites, and most organoarsenic compounds), and +5 (arsenates: the most stable inorganic arsenic oxycompounds. Arsenic and its compounds are used as pesticides, herbicides, insecticides and in various alloys. Arsenic is made on an industrial scale by heating appropriate minerals in the absence of air. The arsenic is condensed out as a solid. FeAsS (700°C) → FeS + As(g) → As(s) Upon heating arsenic sublimes (transfers from the solid to the gaseous state, without passing through the liquid state). You may be exposed to arsenic by taking in small amounts in food, water or air, by burning smoke from arsenic-treated wood, when living in an area with high levels of arsenic in rock or working in a job where arsenic is made or used. Exposure to arsenic can cause many health problems. Being exposed to low levels for a long time can change the color of your skin. Exposure to high levels of arsenic can cause death. 1 2 3 4 5 6 7 Symbol Atomic number Atomic mass Properties Occurrence (Where is it found?) Forms Oxidation states Compounds Uses Production / lab preparation Ways of Exposure Effects of Exposure 7. Now read the text again and complete the second chart with words needed for a description of an element. Nouns Verbs Adjectives symbol occurs crystalline 8. Speaking. Work in pairs. Without looking at the text, try to summarize all the facts that you have learnt about arsenic according to the tables in exercise 6 and 7. 10. Speaking. Work in pairs. Each student should choose 2-3 elements from the periodic table. Try to describe the position in periodic table, properties, occurrence, forms, compounds, uses, reactions etc. Use the standard phrases, structures and vocabulary. The other one has to guess which element it is. You can use these phrases: This element combines with …. to form … It is used as / in ... It is made by … HOMEWORK: Circle the synonym (=word that means the same):^3 1. Chemists study the composition of natural substances. a. materials b. machines 2. Plastic products are hard to dispose of because they are almost indestructible. a. unable to be destroyed b. unable to be constructed 3. Silicon is a nonmetallic element that is inexpensive because it is so abundant in minerals and rocks. a. rare b. plentiful 4. When exposed to air and moisture, iron will corrode. a. rust b. shine 5. After the fire, the police investigated the cause of the combustion. a. burning b. excitement 6. Gasoline should be stored carefully because it is flammable. a. fireproof b. able to catch fire easily 7. Heat can convert a solid to a liquid. a. condense b. change 8. The ammonia was diluted in water to make it weaker. a. thinned b. thickened 9. A catalyst speeds up a chemical reaction. a. chemical agent b. forest animal 10. To obtain aluminum, metallurgists must extract it from bauxite. a. remove b. destroy 11. The temperature on a Fahrenheit fever thermometer ranges from 94° to 108°. a. extends b. contracts 12. The volume of air in a room can be measured in cubic feet. a. quality b. quantity 13. Ten minus four equals six. a. less b. plus 14. Newton computed the weights of the planets. a. measured b. calculated 15. Water contains hydrogen and oxygen in a ratio of two to one. a. proportion b. size 16. The price of gasoline was quadrupled, and there were fears it would go even higher. a. multiplied by four b. divided by four Sources: ^1^ Available at http://www.youtube.com/watch?v=a2AbKwAvyos ^2 Adapted from www.wikipedia.org ^3 Zimmerrman, Fran. English for Science.New Jersey 1989. Lesson adapted from materials by A. Suchomelova-Polomska Useful website: www.webelements.com