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1. Slide 1: Science Interactive LTD Copyright 2005 Science Interactive LTD Science base multimedia CD-ROM for PC is a collection of 38 units or tools totalling over 1150 PowerPoint slides. Each unit covers a wide range of different delivery and learning styles, offering an exciting way to involve your pupils during lessons or revision sessions. All styles of teaching and learning are supported through use of high quality images, graphics, challenging exercises and questions. Units can be used in the classroom via an interactive whiteboard, data projector or used during individual study via a PC or school network. Science Interactive LTD. PO BOX 50764 LONDON NW6 9AT email: sales@science-interactive.co.uk web: www:science-interactive.co.uk Unit 1: The Digestive System Unit 20: Crude Oil and its Products Unit 2: The Circulatory System Unit 21: Rock Cycle Unit 3: Healthy Body and Immunity Unit 22: Elements, Molecules and Compounds Unit 4: The Respiratory System Unit 23: Ionic and Covalent Compounds Unit 5: Nervous System and the Senses Unit 24: The Halogens, their Uses and Compounds Unit 6: Human Homeostasis Unit 25: The Noble Gases, their Properties and Uses Unit 7: Hormones and the Endocrine System Unit 26: Rates of Reaction Unit 8: Drugs and Bad Body Maintenance Unit 27: Energy Unit 9: Photosynthesis in Green Plants Unit 28: Generating Electricity and its Domestic Use Unit 10: Water Transport in Plants Unit 29: Electricity Unit 11: Flow of Energy and Elements through the Environment Unit 30: Light and the Electromagnetic Spectrum Unit 12: Mitosis and Meiosis Unit 31: Radioactivity Unit 13: Inheritance and Selection Unit 32: Newton's Forces and the Effects of Forces Unit 14: Evolution and Human Impact Unit 33: Earth and Space Unit 15: Genetic Engineering Unit 34: The Earth and Plate Tectonics Unit 16: The Periodic Table and its Elements Unit 35: The Alkaline Earth Metals Unit 17: The Alkali Metals Unit 36: Sound and Hearing Unit 18: Metals and their Properties Unit 37: Natural Forces Unit 19: The Transitional Metals Unit 38: Cells, Tissue, Organs and Organs systems
2. Slide 2: Science Interactive LTD Copyright 2005 4 19 2 F He 9 2P+ 9P 10P 35P+ 10N 2N 10N 45N 20 35 10 Cl Ne 2E-- 9E 10E- 35E- 17 Helium Fluorine Bromine Neon 40 80 Br Ar 18 35 18P 17P+ + 36P 53P 22N 18N 48N 74N 84 127 18E- 17E- 36E- I Kr - 53E 36 53 Argon Chlorine Krypton Iodine  Unit 25  The Noble Gases, their Properties and Uses
3. Slide 3: Unit 25: The Noble Gases, their Properties and Uses Science Interactive LTD Copyright 2005 Understand: Keywords: 1. That group VIII elements are called the Noble Elements, Noble, Gases, Unreactive, gases. Electrons, Physical, Properties, Inert, 2. The physical and chemical properties of group Monatomic, Helium, Neon, Argon & Krypton. VIII elements, the Noble gases. 3. That they have similar chemical and physical properties based on their electronic configuration. 4. That because of their full outer shells, the Noble gases do not form compounds with other metal or non metal elements. 5. Understand that their discovery in the atmosphere was hampered by their stability. 6. Some of the main uses of the Noble gases. Click mouse to begin Science Interactive LTD PO BOX 50764 LONDON NW6 9AT web: www.science-interactive.co.uk email: sales@science-interactive.co.uk
4. Slide 4: Science Interactive LTD Copyright 2005 Physical properties of the Noble gases one Group VIII of the periodic table contains a family of very stable non-metals known as the Noble gases. This group contains h________, neon, argon and krypton. They are all monatomic colourless gases. All but helium are found in low quantities in our atmosphere. Helium is found trapped under the bedrock along with deposits of n_________ gas. Helium is so light that the Earth’s gravity is not strong enough to keep it in our atmosphere. Eventually we will run out of helium as it escapes the Earth’s gravitational pull. Give two uses helium and neon ? The Noble gases: Word bank: helium natural Position of the Noble gases The Noble gases Diagram He He2 22 He HeNe10 NeAr1818 Ne10 10 Ne 2 ArAr 1018 Kr36 Helium Helium Helium HeliumNeon Neon Neon Argon Argon Neon Argon Krypton Notes Found in group VIII of the periodic table, The Noble gases have similar chemical and physical all the Noble gases have eight electrons in Kr Kr3636they Kr36 Kr properties because36 all have eight electrons in their their outermost electron shell. They all outer shell. They are all colourless monatomic gases therefore have a full outer shell. This is which do not form ionic or covalent compounds with what makes them very stable monatomic any other elements. They also have extremely low gases. melting and boiling points. Krypton Krypton Krypton Krypton
5. Slide 5: Science Interactive LTD Copyright 2005 Physical properties of the Noble gases two The group VIII elements, the Noble gases are all colourless gases unable to form ionic and c_______ compounds with other elements. They have similar physical and chemical properties. They are all monatomic gases. They have extremely low melting and boiling points which increase slightly as you descend the group. Although they are very s______ they do have many important uses. Why is helium used in airships rather than hydrogen which provides more lift ? Physical properties of group VIII Noble gases: Word bank: covalent stable Element Symbol Formula Electron configuration He Colour Melting point State at room temperature Helium He2 He Ne10 Ar18 s Ne He 2 r les -272oC Gas lou Co Helium Neon Argon He Neon Kr36 Ne He2 Ne10 Ar18 s Ne 2,8 les -210oC Gas ur Kr I Ne lo Co Krypton Helium Neon Argon He Argon Kr36 s Ar He2 Ne10 Ar18 Ar 2,8,8 r les -189oC Gas Kr Ne lou I Co Krypton Helium Neon Argon Kr I Krypton Kr 36 s les Kr He2 Ne 10 Kr36 2,8,18,8 r -179oC Gas ou Kr I l Co Krypton Helium Neon Krypton Ar Kr
6. Slide 6: Science Interactive LTD Copyright 2005 The discovery of the Noble gases The noble gases were not discovered until about the turn of the last century. Because the Noble gases are highly un-reactive, they remained hidden in the a____. Helium was discovered with deposits of natural gas found under the bedrock. In 1892, scientists discovered that, when all the nitrogen and oxygen from a sample of air was reacted with hot magnesium, there was around one percent of the gas that would not react. This small fraction contained n______, argon and krypton. Discovery of the Noble gases: Word bank: air neon Percentage composition of noble gases in air Using helium Diagram % composition of noble gases 1 100 0.5 50 0 Argon Neon Helium Krypton 0 Nitrogen Oxygen Noble gases CO2 Notes The Noble gases were not discovered until 1892 due to their Hydrogen although having stability. They make up only 1% percent of the atmosphere. greater lift has now been Although they are stable they are still useful. replaced by stable helium.
7. Slide 7: Science Interactive LTD Copyright 2005 Helium and its uses Helium is the least dense of the Noble gases. A balloon full of helium will have lift in normal air. Although hydrogen gives more l_____ because it has the lowest density of any of the elements it is also highly reactive. Helium makes for a safe alternative and is used in airships and ‘party balloons’ Helium is also used by deep seas divers instead of nitrogen. It has a low solubility and therefore reduces the risk of divers suffering the bends. This is when nitrogen in the blood comes out of solution and begins to bubble in the b_______. This can be fatal. Why is this condition called the bends ! Helium and its uses: Word bank: lift bubble Helium Using helium for lift Helium balloons Diagram He2 Ne10 Ar18 Notes Helium is a low density stable gas that gives Helium is also used for ‘lift’ to objects like balloons in air. Hydrogen party balloons. They are is better but it is also very unstable and can able to rise above the air. They also (when breathed Helium react with the oxygen in the Argon Neon atmosphere in) make you sound like forming water. This is an explosive reaction. Mickey Mouse.
8. Slide 8: Science Interactive LTD Copyright 2005 Neon and its uses Neon is the most widely used Noble gas. Neon is used to make fluorescent light tubes, which can take on many colours. When you pass a high v_______ current across a tube full of n______, it glows and gives off light. The tubes can be coloured using various dyes making them ideal for use in advertising signs around the World. If you take a trip to London’s Piccadilly Circus, then you will see hundreds of flashing neon signs all advertising various products and fast food companies. Explain why a neon light uses less energy than a normal filament bulb ? Neon and its uses: Word bank: voltage neon Neon Neon lights at Piccadilly circus Choose a colour Diagram He2 Ne10 Ar18 Notes Scientists found out that when you pass a high By colouring the glass voltage current through a tube filled with tube you can colour the neon, it fluoresces. Neon lights are used in light that is emitted. Neon lights do not produce any Helium Neon advertising signs. There are also more energy Argon heat and are therefore efficient compared to filament bubs. much more efficient.
9. Slide 9: Science Interactive LTD Copyright 2005 Argon and its uses Argon makes up nearly one percent of the composition of atmospheric air. Argon is more dense than air, so balloons filled with just argon appear to ‘sink.’ Argon has two main uses. Argon is used to replace air or o________ where you need an oxygen free environment in order to prevent combustion. Filament b______ made from tungsten contain argon to prevent the tungsten from oxidising with oxygen. Argon is also used during the welding of metals to prevent metals combusting with oxygen. What other processes require an oxygen free environment ? Argon and its uses: Word bank: oxygen bulbs Argon Using argon during welding Light bulbs Diagram e10 Ar18 Notes During welding very high temperatures would Light bulbs are filled with cause most metals to begin to react with inert argon gas so that the oxygen found in air. Argon is flowed over the tungsten filament does not begin to form tungsten Neon Argon weld to prevent the metals reacting. This oxide with oxygen from techniques is called ‘argon welding’ the atmosphere.
10. Slide 10: Science Interactive LTD Copyright 2005 Krypton and its uses Krypton makes up a very small fraction of the composition of atmospheric air. Like argon, krypton is more d______ than air. Krypton has one main use. Krypton is used to produce high energy lasers. These lasers are seen in disco lighting shows. They also carry sufficient energy to melt metal during their w________. When a high voltage current is applied to the krypton gas, a high energy light is emitted that is used to produce laser light. Find out from google.co.uk how laser light is produced ? Krypton and its uses: Word bank: dense melting Krypton Krypton lasers Eye surgery Diagram e10 Kr36 Notes Krypton is used in lasers used for disco Krypton lasers are use to lighting and welding. A high voltage current remove excess corneal is applied to the krypton gas which produces a tissue during laser eye correction. The cornea is Neon Krypton high energy beam. This energy is sufficient to reshaped to give the cause melting in metals during welding. correct focal length.
11. Slide 11: Science Interactive LTD Copyright 2005 Extension questions and homework 1: Define the following terms: Elements, Reactivity, Noble Gases, Inert, Ionic and Covalent. 2: Look at the three pictures below. Complete the table. Picture Element Properties and uses One Krypton Two Neon Three Helium 3: Answer the following using the following table: Inert Monatomic One percent Diatomic Reactive Lift Light bulbs Hydrogen Sign Lasers a) How much (percent) do the noble gases make up of the atmosphere. b) This gas was used to give lift to air ships. c) Argon is used in this device to stop the filament from combusting with oxygen. d) Whereas, the halogens are diatomic gases, the noble gases are what type of gas. e) All noble gases are said to be chemically what.
12. Slide 12: Science Interactive LTD Copyright 2005 4: Complete the following table. Gas Electrons in outer shell State at room temperature Colour Symbol Helium 2 Neon Gas Argon colourless Krypton Kr 5: Answer the following questions: a) What would happen when a light bulb is switched on and it is filled with normal air. b) Airships are no longer filled with, hydrogen. Helium is now used. Explain why. c) Explain why there are no known compounds that contain either helium, neon, argon or krypton. d) Why do helium balloons deflate more quickly than balloons filled with atmospheric air. e) How many electrons do (i) group I alkaline metals have in their outer shell (ii) The group VIII noble gases. f) Explain why the melting and boiling points of the nobles gases increases as you descent the group. 6: Look at the information in the table opposite: Element When found a) Why were the noble gases discovered very late and why do they Gold < 2000 B.C have similar properties. b) Why is neon used in advertising signs. Helium 1895 c) Why will we eventually rum out of the element helium. Neon 1898 d) Why is argon used to replace air in light bulbs. Oxygen 1774 e) Give two uses of a krypton laser. Phosphorus 1669 Internet: Go to google.co.uk and find out the ‘Hindenburg disaster’ where hydrogen, not helium was used as a lifting gas for this airship.