Air And Water Booklet  More Resources 

science education teaching booklet

Name:________ The Air: The Earth is surrounded by a layer of gas which we call air. Air is a mixture of several different gases. The Earth's atmosphere contains several different gases. Most of it 78 % is nitrogen. Almost all of the rest 21 % is oxygen. The rest is made up of very small amounts of carbon dioxide, argon and other noble gases, and water vapour. Gases in the atmosphere Gas Nitrogen Oxygen Argon Carbon dioxide Neon, krypton, xenon, water vapour Percentage 78 21 0.9 0.03 very small amounts oxygen nitrogen argon Carbon Dioxide other gases The atmosphere is made of air, while space is where there is no air. The atmosphere is divided into three major layers: 1 Lower atmosphere: Known as the troposphere, this layer contains about 80% of the air. Its thickness varies from 10 km at the poles to 15 km over the equator. All our weather happens in the troposphere. Clouds exist in this layer. The air moves around the Earth and moves up and down within this layer. As you go higher, the air pressure decreases and the temperature decreases from 20°C to -60°C Above the troposphere the atmosphere gets warmer. 2 Middle atmosphere consists of: • The stratosphere is a layer that extends from 11 km to 50 km. The temperature rises from -60°C to +20°C. The air moves horizontally and does not move up and down. • The mesosphere extends from 50 km to 90 km. The temperature decreases from +20 to -86°C as you go higher. 3 The upper atmosphere or ionosphere: It consists of: • The thermosphere extends from 90 km to 480 km. This is the hottest layer because it is closer to the Sun. The temperature increases from -86°C to more than +600°C. • Exosphere: This starts at the top of the thermosphere and continues until it merges with the space, which mainly contains hydrogen and helium gases. Between 200 to 480 km, charged particles from the Sun change some of the atoms into ions (= charged 2 particles). These charged particles cause auroras near the north and south poles. The ions reflect radio transmissions back to Earth. Ozone Layer While there is some ozone in the air we breathe, most of the ozone in the atmosphere is in the upper stratosphere. Even though ozone makes up only a small part of the stratosphere, it is often referred to as the ozone layer. Ozone is especially important to life on Earth because it blocks out more than 95 per cent of the sun's ultraviolet (UV) rays. Any decrease in the amount of ozone in the stratosphere is damaging to all living things because more UV rays reach the surface. For humans, this means a greater risk of the sunburn and skin cancer these rays cause. Some chemicals used by humans drift up into the stratosphere, causing chemical reactions that reduce the amount of ozone. These chemicals include CFCs (chlorofluorocarbons), which were used in aerosol spray cans and older air conditioners and refrigerators. EXPERIMENT MAKE YOUR OWN ZINC CREAM AIM To find out how chemists make the zinc cream we use on our noses to prevent sunburn. MATERIALS • • • • • • • • • Caution: Zinc cream made in the laboratory should not be used on skin unless sterile equipment has been used. 50 ml light liquid paraffin 10 g soft micro wax 20 g zinc oxide large beaker thermometer (up to 100°C) hotplate stirring rod container with lid to store zinc cream non-toxic wax crayon (optional) 1 2 3 Melt the paraffin and micro wax in a beaker over a low heat. Use the thermometer to check that you don't go over 80°C. If you would like to make coloured zinc cream, add a small non-toxic wax crayon at this melting stage. Remove the beaker from the heat when the wax is melted. Gradually add the zinc oxide, stirring well with the glass rod between each addition. Allow the mixture to cool and transfer to a container. METHOD Keeping the atmosphere balance The air in the atmosphere is needed by plants and animals, which need oxygen to live. In breathing, animals replace the oxygen with carbon dioxide. During the day, plants use carbon dioxide to help them make their own food. In doing so, they produce and release oxygen. Fuels that are made of the remains of dead animals and plants are called fossil fuels. Coal, oil, gas and petrol are fossil fuels. When fossil fuels are burnt by power stations, cars, factories and in homes, oxygen is used up and carbon dioxide is released. 3 Together, plants and animals help to keep the amounts of oxygen and carbon dioxide in the atmosphere in balance. The amounts should not change much at all. The atmosphere should be in balance. However, the balance is under threat. The amount of carbon dioxide in the air is increasing. There are two main reasons for this: 1. The burning of fossil fuels. The people of Earth are using more fossil fuels every year. Australians add about 70 million tonnes of carbon dioxide to the atmosphere each year by burning fossil fuels. 2. The clearing of forests. Trees absorb carbon dioxide from the air and produce oxygen. As they are cleared, another means of keeping the atmosphere balanced is removed. In Australia, twothirds of all forests that existed 200 years ago have been cleared. Greenhouse effect Heat from the sun enters the atmosphere and warms up the Earth's surface. At night, this heat escapes through the atmosphere. Without the atmosphere, too much heat would escape and the Earth would be bitterly cold at night. The gases in the atmosphere trap some of the heat. This trapping of heat is called the greenhouse effect. Scientists are now concerned that the carbon dioxide produced by burning fossil fuels is building up in the atmosphere. This extra carbon dioxide traps more of the heat that is radiated from the Earth. Scientists predict that the Earth will become warmer, and that this will cause major changes in the Earth's weather. The glass in a greenhouse lets sunlight through but traps the heat inside. Carbon dioxide and water in the atmosphere absorb the heat, which is radiated from the Earth. This keeps the Earth relatively warm at night. 4 Green House Experiment Aim To set up a model greenhouse Materials • • • • • 2 microscope slides adhesive tape 2 small cardboard boxes 2 thermometers stop watch 1 2 Lay the two slides side by side and tape them together. Then cut a hole in both boxes as shown. Lay the slides over the hole on one of the boxes. Punch a hole in the end of the box and insert a thermometer as shown below. This is your model greenhouse. 3 To see how effective your greenhouse is, set up a control box. This time it is the same 'house' without • Record the temperatures on both thermometers before you take the boxes out into the sunlight. Leave the greenhouse and the control in the sun for about 20 minutes. • Record the temperatures every 2 minutes during that time. Method 4 Results Time (Minutes) Temperature (o Celsius) 0 2 4 6 8 10 12 14 16 18 20 Plot temperature against time for the greenhouse and the control on the axis below. Green House effect 70 60 Temperature (Celsius) 50 40 30 20 10 0 0 5 10 Time (minutes) 15 20 25 Key 5 Questions and conclusions 1 Compare the green house and the control what can you say about the differences. ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 2 Use the greenhouse model to explain how the atmosphere affects the temperature on Earth. ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ EXERCISES 1 Some of the following statements are false. Find the false ones and rewrite them to make them correct. (a) The troposphere is the layer of the atmosphere closest to the Earth's surface. (b) The stratosphere contains more dense air than the ionosphere. (c) Auroras occur in the mesosphere. (d) Most weather changes occur high up in the stratosphere. ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 2 In which layer of the atmosphere do you live? ______________________________________________________________________________________________________ 3 The highest mountain on Earth is Mt Everest, at 7600 m. In which layer of the atmosphere is the mountain's peak? ______________________________________________________________________________________________________ Lyndell told Angus that she was cold last night. Angus said that, unlike last night, tonight would be cloudy and he predicted that this would make it much warmer. On what knowledge did Angus base his prediction? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 5 Mountain climbers scaling very tall mountains have to carry oxygen tanks. Suggest a reason for this. 4 ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 6 What is ozone? Why is it so important for life on Earth? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 7 How would you increase the accuracy of this experiment? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 6 Cars, greenhouse and Kyoto Greenhouse effect Like the air in a greenhouse (or glasshouse) the Earth's atmosphere traps some solar radiation and warms the surface of our planet. About 10% of the energy reaching Earth as solar radiation is reflected by dust particles in the air or from the surface of clouds. Gases in the atmosphere, mainly carbon dioxide, ozone and water vapour, absorb much of the nonvisible solar radiation that reaches Earth. These are known as greenhouse gases. Ozone absorbs UV radiation, while carbon dioxide, water vapour and clouds absorb most of infrared radiation. The average temperature of the Earth remains relatively stable when the proportion of these gases in the atmosphere is balanced. Without the greenhouse effect of these gases the Earth's average temperature would be around -18°C rather than 15°C, affecting weather conditions, plant growth and animal growth. Atmosphere scientists fear the balance of these gases has been upset so that we have what they generally refer to as the enhanced greenhouse effect (often just called the greenhouse effect), an increase in the amount of heat being retained by the atmosphere. Other greenhouse gases, such as methane, nitrous oxide, chloroform, and chloro-fluorocarbons (CFCs), have also increased in concentration or have been introduced into the atmosphere as a result of the industrialisation of our society. Methane (CH4) is formed from the breakdown of organic matter. Cows and sheep produce methane from the bacterial digestion of cellulose. Rice paddies, garbage tips, coal mines and natural gas fields also release quantities of methane. Nitrous oxide is produced in car exhausts and through many industrial processes and the use of nitrogenous fertilisers and burning of forests. Chlorofluorocarbons were invented in the 1920s and were widely Did you Know used in refrigerators, as propellants in aerosol cans and to create the There is evidence from bubbles in plastic foam. Concern about their effect on the ozone ice core samples taken layer has led to international agreements to phase out their use. in the Antarctic that the CO2 concentrations Kyoto Agreement in the atmosphere The United Nations Framework Convention on Climate Change was have increased by held in Kyoto Japan during December 1997. Here, many countries 25% in the last 200 agreed to reduce their emissions of greenhouse gases. However, the years. Australian government would only agree to limiting the growth of emissions but not to reducing them. In 1994, Australia's total greenhouse gas emissions were calculated to be approximately 576 million tonnes. The main sources of these gases were motor vehicles, electricity production and land clearing. 7 1 Activity How does the Earth's atmosphere maintain relatively stable surface temperatures? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 2 What factors affect how much solar radiation reaches the Earth's surface? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 3 The amount of water vapour in the atmosphere is not likely to be altered directly by human activity. What factors would cause the concentration of water vapour to increase? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 4 Why do you think the amount of methane in the atmosphere has increased so dramatically? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 5 Deforestation is a major environmental issue not only in terms of the logging of native forests but because it contributes to the enhanced greenhouse effect. How would this practice cause changes in the concentration of greenhouse gases? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 6 Do you think there are advantages to an enhanced greenhouse effect? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ The Particle Theory of Matter (Revision) This theory includes the following ideas: • All matter is made of small particles. • These particles are always moving. • When matter is heated these particles move faster. • When moving faster, particles occupy more space. • When matter is cooled the particles move slower. • When moving slower, particles occupy less space. • Forces that vary in strength hold particles together. • • • • Solids The particles are as close together as they can be. Particles can only vibrate in fixed positions. Particles are not free to move. Particles are held together by strong forces of attraction. • • • • Liquid The particles are as close together as they can be. Particles are held together less strongly. Particles are not free to move. Particles can roll over one another. 8 • • • • • Gases The particles are much further apart. Particles are not held together. Particles are free to move. Particles move randomly in all directions. Attractive forces between particles are very weak. Activity a. Matter is made up of small __________. b. These particles are always ___________. c. These particles move __________ in a hot substance than in a cooler substance. d. The particles of matter are held together by ____________. e. Particles in a solid can only __________ in ____________ positions. f. Particles in a liquid can ___________ over one another. g. Particles in _____________ move freely. h. Particles in ____________ and _______________ are as close together as they can be. i. Because particles in gases are ____________ apart, they can be ____________. together as they can be. k. Liquids can be poured because their particles can _______________ over one another, l. Solids cannot be _____________ because their particles are in fixed ___________. m. Because particles in gases are _________ to move, they, like liquids, can also be _________. j. Solids and liquids cannot be compressed because their ___________ are as ____________ Particles and pressure Each particle in a gas has energy and can push against anything that it hits. In a gas the particles are very tiny, so their energy is very small. But there can be billions of particles in just 1 mL of gas. The total push of these particles is very big. It is called gas pressure. In air it is called air pressure Gas pressure depends on: • the number of gas particles—the more particles there are, the more they push and the greater the pressure • the speed (energy) of the particles—fast particles are at a higher temperature and push harder than slow particles When a tyre goes flat, it has lost most of its air. There are no longer enough air particles inside the tyre to push it outwards. An aerosol can contains gas at high pressure. There is a lot of gas compressed in the can. The valve on top is like a gate that lets the particles out. When you release the valve, some gas particles are pushed out by the other particles. The constant fast motion of the gas particles causes the pressure in an aerosol can compressed gas particles 9 Blowing up a ballon Take Blowing up a balloon and blow it up until it is fully inflated. Tie up with a string and notice the shape and size of the balloon. Take another balloon and blow it up until it is about half full. Balloon 1 Balloon 2 100 air particles 50 air particles 1. 1 Balloon 1 has _____________ gas particles inside it, and there is more ____________________ inside the balloon pressing on the balloon skin. 2. Balloon 2 has ___________________ gas particles and there is ____________air pressure inside the balloon pressing on the balloon ____________ so It Is smaller. Pressure and temperature Obtain two flasks and fit a balloon over the top of each flask. Each flask contains only air. Place the first flask into a beaker of warm water. This warms the gas and the gas particles move faster. Notice the shape and size of the balloon. Put the second flask into a refrigerator or freezer. After ten minutes observe the shape and size of this balloon. Cold Hot 1. When the gas in the flask was heated, the gas particles started to move _______________ and take up ______________ space, so the balloon go t _______________ 2. When the flask was cooled, the gas particles moved ______________ and took up less space. Water pressure Take an empty drink bottle and punch three holes in a line down one side of the bottle. Place your fingers on the holes and fill the bottle with coloured water. Take your fingers off the holes and observe whether the water comes out of each hole with the same force. 1 2 3 Draw how the water comes out of each hole on the diagram on the left. Water comes out with greater force from ___________ hole because the pressure __________with depth. As you get deeper in the ocean the water pressure ______________. 10 Activity Refer the previous 3 experiments a. What is teacher trying to show or teach you with the balloon drawings labelled "100 air particles" and "50 air particles"? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ b. What conclusion may we come to about gas pressure and gas temperature? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ c. Look at the diagram of the flask and the balloon. Now say what else may increase if gas temperature rises? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ Under pressure When you are landing or taking off in a plane, your ears 'pop'. If you climb steeply, the air pressure inside your middle ear remains the same while the air pressure outside drops. The air inside pushes on the eardrum causing an uncomfortable feeling. The 'popping' is caused as the Eustachian tube, which is normally closed, opens. This allows a i r to rush out of your middle ear to your nose and mouth. The pressure is then the same on both sides of the eardrum. When you descend quickly the 'popping' occurs as the air rushes Into your middle ear to balance the Increasing pressure outside. If you swallow hard you can make the 'popping' happen sooner. Density Density is a measure of how closely particles are packed together in a material. If the atoms in a material are packed very tightly together, the material will have more mass (a greater number of atoms) and therefore weigh more. These materials are said to be very dense, for example lead. Materials such as marshmallows don't have many atoms but they do have a lot of air between the atoms, so they don't weigh much and are less dense. Gases are even less dense, and do not weigh much at all. How heavy something is depends on its size and its density. Measuring Matter • Weight — the weight of something depends on its mass and how much gravity is pulling on it. A sugar cube on Earth has the same number of atoms as a sugar cube on the moon but it will weigh less on the moon because there is less gravity. • Mass is easy to work out — just put the object on some scales and measure how many grams it weighs. • Volume can be measured by dropping the object into water and measuring the volume of water it displaces, or pushes aside (1 millilitre = 1 cubic centimetre). • Density can be calculated by dividing the mass (grams) by the volume. Density ( g / ml ) = Mass( g ) Volume(ml ) 11 Buoyancy Experiment Aim To investigate the effects of buoyancy • • • • Materials small round balloon spring balance (Newton scale) piece of string (30 cm long) aquarium (share with class) Fill a small round balloon with water and tie up the end. Lay the balloon on the bench. Observe its shape and draw it in your results. Tie some string around the end of the balloon so that you can suspend it from spring balance. Find the weight of the balloon. Method 1 2 a Observe the shape of the balloon. • Record your results. 3 4 Suspend the balloon in an aquarium full of water. Observe the shape the balloon and again find its weight. Let the balloon rest on the bottom of the aquarium. How does its shape compare with its shape lying on the bench? of Results Diagram of Balloon on spring Diagram of Balloon on table balance Mass of Balloon = Diagram of Balloon in aquarium Mass of Balloon = 12 Questions and conclusions 1 Compare the weights of the balloon in water and in air. Infer what caused the difference. ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 2 Water has a buoyancy effect on the weight of objects. From your results, what do you think 'buoyancy' means? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 3 Why is it that beached whales often break their bones, particularly their ribs? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ Buoyancy in water Why do you feel almost 'weightless' when swimming in water? What we feel as an upward 'push' is called buoyancy. This buoyancy is greater in water than in air because water is denser than air. Salt water has a higher density than fresh water so the buoyancy effect is greater and you float better, or feel more buoyant, in salt water. Aquatic animals can easily swim around in water but some are crushed by their own weight on land. For example, jellyfish float in seawater but are flattened when stranded on the beach. Whales are so heavy that when beached, they are virtually unable to move and often die. In the ocean, their weight is supported by the buoyancy force of the water. Soluble and insoluble substances Many substances will dissolve in water. These substances may be described as water-soluble. A soluble substance is one that can dissolve in another substance. Substances that do not dissolve in water are called waterinsoluble substances. Insoluble substances do not dissolve. When a substance dissolves in another substance, a solution is formed. A solution is clear, that is no particles can be seen. The substance that takes in, or dissolves, other substances are called the solvent. The substance being dissolved is called the solute. If sugar is mixed with water, for example, a solution is formed since the sugar dissolves. The water acts as the solvent and the sugar is the solute. A sediment may be formed when insoluble substances settle to the bottom of the container they are in. A mixture in which some or all of the particles settle out is called a suspension. Solutions are not always made up of a solid dissolved in a liquid. Liquids and gases can also dissolve in solvents. A solute dissolves in a solvent to form a solution. 13 Liquid dishwashing detergent dissolves in water. Two-stroke motor fuel, used in lawn mowers and outboard motors, is a solution of oil in petrol. In soda water and soft drinks, carbon dioxide gas is dissolved in water and bubbles out when you take off the lid. Oxygen is only slightly soluble in water but sufficient oxygen can dissolve in water for fish to breathe using their gills. AIM • • • • SOLUBLE AND INSOLUBLE SUBSTANCES A suspension settles on standing to form sediment. To investigate the differences between soluble and insoluble substances. MATERIALS 6 test-tubes labelled A, B, C, D, E, F test-tube rack rubber stoppers small quantities of the substances in following Table 1 2 Place 30 ml of water in each of the six test tubes and then to each test-tube A, B, C, D, E and F add a small quantity of the substance listed in Table. Place a rubber stopper in each of the test-tubes in turn and shake the tube gently. (If you are reusing a stopper, rinse it in water between test tubes.) Safety: Never put your finger or hand over a test-tube to shake it since what is in the test-tube may be poisonous or may burn you. As you shake each tube, hold it up to the light. Is it cloudy, or does the light shine through it? Is the liquid coloured or colourless? Allow the test-tubes to stand in the rack for five minutes. Have any of the substances you added to the water settled to the bottom? Record your observations in the Table. Substance soluble (Yes/No) METHOD 3 4 5 Results Test-tube A Substance copper sulfate Observation B salt C copper carbonate D sugar E chalk F sand 14 DISCUSSION 1 Which of the substances you tested were soluble and formed a solution in water? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 2 Which of the substances you tested were insoluble in water? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 3 Did any of the insoluble substances form sediments if so which ones? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 1. Complete the following sentences: When one substance dissolves in another a _____________ is formed. The substance which dissolves is the ___________ and substance in which it dissolves is the _____________ . ______________ is the most common solvent. Any substance that does not _____________ in a solvent is said to be ___________________ in that solvent. 2. Many substances that are insoluble in water will dissolve in another solvent. Make a list of five such substances and include the name of both the solute and the solvent. ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ 3. In your own words describe the difference between dissolving and melting. ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ ______________________________________________________________________________________________________ Activity 15 FEATURES OF A WEATHER MAP Isobars Places with equal barometric pressure are joined by lines called isobars. Isobars are continuous lines joining areas of equal barometric pressure. Pressure systems Major features of the weather map include high and pressure systems. High pressure systems are sometimes referred to as anticyclones and low pressure systems as cyclones or depressions. Pressure systems over southern Australia generally move from west to east. Their movement is variable systems may become stationary. The systems change with time as they develop, intensify, weaken and eventually die out. The weather maps produced daily and found in the media are for surface conditions only and accurate forecasting without upper atmospheric information is difficult. The Bureau of Meteorology uses satellites, radar and radiosondes to obtain a three dimensional picture of the weather. Figure 1 - Weather Map High or anticyclones Highs or anticyclones tend to be elliptical and when greatly elongated are known as ridges or wedges of high pressure. In a high pressure system the winds circulate in an anticlockwise direction. This combination of air movement from high to low pressure and the earth’s rotation causes the winds to blow approximately along the isobars, but with some deflection outwards from the centre. However, for most purposes it is satisfactory to assume that winds blow parallel to the isobars. An anticyclone approaching from the west indicates that the following events are likely to occur: • • • • Clearing skies; Lighter winds; Higher temperature; Lower relative humidity High pressure systems are large masses of air that are subsiding and therefore warming and drying as they approach ground level. Temperature inversions are common, moisture levels are lower and the vertical development of clouds is therefore unlikely. High pressure systems provide dry, warm weather with the possibility of a lead up to critical fire weather. 16 Lows or depressions In a low-pressure system the winds circulate in a clockwise direction, approximately along the isobars but with some deflection towards the centre. Again, for most purposes it is satisfactory to assume that winds blow parallel to the isobars. The following effects are likely: • Increasing cloud; • Increasing moisture in the atmosphere; • Unstable weather; • Rain Low pressure systems are board areas of slowly ascending air which cools and becomes more moist as it rises, producing cloud and instability and therefore an increased likelihood of rain. Low-pressure areas are therefore significant to fire suppression Figure 2 - Wind Strength contrasting ways; the possibility of rain to help suppress fires versus the possibility of dry thunderstorms producing multiple ignitions from lightning strikes. in Wind Strength Wind strength is proportional to the pressure gradient that is shown by the spacing of the isobars. Where isobars are closest the winds are strongest, and where they are widely spaced the winds are light. Activity 1. On the following diagram draw lines joining the places with equal air pressure. 2. Mark on the map any highs and lows 17 Find each of the following words. SOLUTE LIQUID DENSITY STRATOSPHERE OXYGEN METHANE PRESSURE TROPOSPHERE SPACE SOLID MESOSPHERE MATTER TEMPERATURE OZONE GREENHOUSE DISSOLVE BUOYANCY PARTICLE VACUUM BALANCE SOLVENT GAS ATMOSPHERE KYOTO D T H T V T N E V L O S H Y G R H E M I E E L C I T R A P E A D E B N M B U O Y A N C Y H L X X M N A S L E T V A C U U M A M P S I E L I I E M E C A P S T E S T U P K A T Q S Y Y U Y G M T Y M E R O Y N Y U D S T O S O H U R C E S S O C I I P R S S S A A E E S H G N T E S D O R T P N E A N S A R C E O S E P M R H E H R O U O E O R R O D O A A E T U T E R O E S E E L O S T T R E H E O E X N I G R V D P T O E C T M T E Y H V N A E N H E S O P T P O O G O T E A S N E R P O P P E Z O E U E E O E T R T H L E E R O N N S Y L T T G E Y E E C G A N Y A E U E E E A S E R E S E T E R E T U T A O S I E E O N B U E R E H P S O S E M P L E T O R R E O R O T R S E R I L O L M E R U E U A S Y U E D E D E V S Q O A I S R A E U E I A E O V Y 18 Gas Nitrogen Oxygen Argon Carbon dioxide Neon, krypton, xenon, water vapour Percentage 78 21 0.9 0.03 very small amounts Gases in the atmosphere oxygen nitrogen argon Carbon Dioxide other gases 21