Expansion and Contraction of Matter

SMJK AVE MARIA CONVENT SCIENCE B6D7E1 The Principles of elaboration and abbreviation of matter Name Lim Li Fern (14) Class 1P11 Identification Card no(prenominal) 990412-11-5206 Subject teacher Puan Norlida soup up does to matter is changes it state. There is something more shrewd though that arsehole cause big problems. Look at this devise. When you alter both this eyeb all told and the ring the ring brandishs interchangeable a coarse bar of metal. Theball expands less so when they atomic number 18 alteredthe ball fits through the ring. You may want to look for these and try this demo as many of you probably feature these. A nonher neat in like mannerl to betoken the elaboration of metals is this bimetal bar.It is made with champion metal on one side and an otherwise metal on the other side. One metal expands more rapidly so the bar twists when wake uped. This affects things in the real human drastically. If this is non considered when building something we can can up with a high personal manner buckling. Engineers then plan for the expansion and wedgeion due to heat. In a pipe we may impose special activates likethisorthisso that the pipe can expand in length without breaking. demeanour of matter Expansion and contractioncontraction Substancesexpandor lead bigger when they are heated up. Theycontractor get smaller when they are cooled down feather.This property can be useful. * Thermometers work because the molten indoors them expands and rises up the tube when it gets sweltryter. * surface parts can be fitted together without welding victimisation cower fitting. The animation shows how this works. Expansion and contraction in metal The pole is too big to fit through the hole. The rod is cooled, causation it to contract. The rod fits in the hole. When warmed, it expands to fit tightly. All matter is affected by heating system and cooling. With a real few censures, when any matter is heated, it go away expand. When it is cooled, it will contract. spy a Gas Expand When Heated part Place the neck of the balloon all over the mouth of the bottle. Put about 6 cm (2 in) of urine in the bottom of the cumulus and go under the bottle and balloon in the pot. Heat the water slowly over the stove. You do not need to heat the water to boiling. What happens to the balloon? convey the bottle and allow it to cool. What happens to the balloon at present? What HappenedWhen the air inside the bottle was heated by the lively water, it expanded. As the air expanded, somewaspushed into the balloon ca using it to expand slightly. When the air inside the bottle cooled, it contracted and the balloon shrank.Observing a Gas Contract When Cooled entirely as you saw a gas expand when heated, you can look out how it contracts when cooled using the same material as in the last experiment. ProcedurePlace a couple of inches of water in the bottom of the pot and place the bottle in the pot. Heat the water to almost bo iling. Then, using the oven mitts, remove the bottle and quickly place the balloon over the neck. free the bottle to cool and observe the balloon as the bottle cools. What HappenedAs the air inside the bottle cooled, it contracted. This ca apply the balloon to be drawn into the bottle.Observing a Liquid Expand When Heated Procedure Put a footling food coloring or a pinch of coffee or fruit drink mix in the bottle. gratify the bottle only with cool tap water. Place a couple of inches of water in the bottom of the pot and carefully place the bottle in the pot, universe careful not to spill any of the water. Slowly heat the water in the pot almost to boiling and observe what happens to the water in the bottle. What HappenedAs the water inside the bottle was warmed, it began to expand. The bottle could no durable hold all of the water and the water began to bulge from the top.Some may accept even spilled out. Observing a Liquid Contract When Cooled ProcedureFill the bottle comple tely to the top with hot tap water. Try to get as few bubbles in the water as possible. Allow the bottle to cool where it will not be disturbed. Be careful not to spill any of the water. After the bottle has cooled to room temperature, observe the level of the water in the bottle. What HappenedThe water level was slightly below full. As the water cooled, it contracted make the water level to drop. However, at that place may also be another effect here as vigorous.If you used water with a lot of bubbles, those bubbles also took up a part of the flock inside the bottles. As the bubbles eventually floated to the top, they would have decreased the volume slightly. Can you think of some way to insure that what you are sightedness is not a result of the bubbles? A Major Exception to the rationale The general rule that has already been stated is that matter expands when heated and contracts when cooled, precisely there are a few exceptions. The most important exception is water when it freezes. Procedure Fill the bottle to the top with water and switch the cap.Wrap the bottle in several layers of news composing and place the bottle and paper in the bag. Put the bag in the freezer and leave it there until the water freezes. Remove the bag and paper and examine the bottle. What do you see? What HappenedThe bottle was shattered or very swollen. When water is cooled, whether as a gas (water vapor), a liquid, or a solid, it will contract. The one major exception to this is when water reaches the halt mind and changes from liquid water to ice. At that point, the water expands, rather than contracts. This expansion caused the bottle to break.The reason water behaves this way has to do with the shape of its molecules. When water freezes into ice, its molecules line up in a certain way, and when they do, they riposte up more space than they did as a liquid. It is almost as if the molecules elbow each other out of the way, and this causes the ice to take up more s pace than the liquid water. Once the water freezes and gets c sometime(a) than the freezing point ( 0? C or 32? F), it begins to contract again. The only time water expands when cooled is at the point where it freezes. However, the fact that water expands when it freezes is very important in nature.For example, one of the slipway that jars are broken down into soil is by water freezing in the cracks of rocks. When the frozen water expands, it has enough force to cause the rock to split or break into smaller and smaller arranges. Observing a Solid Expand and Contract ProcedureUsing the conducting wire break upters, cut a rod from the long bottom section of a wire coat hanger. Keep this wire as straight as possible. function the sandpaper to sand the winder off the wire. (You are going to heat this wire, and you need to remove the paint to avoid fumes from burning paint ) Cut a section of the coffee stirrer or cusk straw about 3 inches long.Push the straight pin through the p osition of this section. The straight pin should fit snugly. If it doesnt, use a small piece of tape to hold it in place. Set up the rod, pin, books and heat seminal fluid as shown. Make sure that the end of the rod away from the cursor is firmly against a book, and that the rest of the rod is touching only the pin, and not the surface of the books. Heat the rod using your heat source, and observe what happens to the pointer. Remove the heat source without disturbing the rod and watch what happens as the rod cools. What HappenedAs the rod was heated, it began to expand.Since one end of the rod was against the book, it could expand in one direction only. As it expanded, the rod moved over the pin, causing the pin to roll slightly. Although the pin may not have roll more than a quarter turn, the pointer allowed you to see this motion very clearly. As the rod cooled, it contracted and moved the pin and pointer punt to where they started. We have seen that solids expand when heated a nd contract when cooled. Engineers who design roads, buildings, towers, and other great(p) structures must know how much a substance will expand or contract over the range of temperatures it is expected to encounter.The engineers then have to design the structure to prevent damage from expansion or contraction. These next experiments will have you to examine some of these structures on a hot day in summer and a icy day in winter. They could become part of a science project on heating and cooling. Expansion and abbreviation of Railroad Tracks Raildroad Track Expansion Joint head along a railroad track until you find a place where deuce rails are joined together. You should see a small gap between the rails where they are fastened together. This gap is called an expansion joint.Some newer tracks have rails that are continuously welded together and do not use expansion joints. If you walk for some distance and do not see a gap between both rails, the tracks you are looking at are probably of this kind. If possible, you should try to locate an older track, or even one that is no longer in use. much(prenominal) track will be more likely to have expansion joints. If you are able to locate an expansion joint, measure and write down the outside temperature, along with the date and the time. Also, measure and record the size of the gap. The mm scale is probably the best scale to use.If you have a camera (particularly if this is part of a science project) take a bear witness of the joint. It is a good idea to take this picture with the ruler in place. take over your notes. If you did this on a hot day, repeat it on a refrigerating day, or vice versa. Can you measure any difference in the size of the gap? What HappenedThe gap is slightly narrower on a hot day, because the rail sections on either side of the gap expandwith the increase heat. If expansion joints were not put in place and the rails were put tightly together on a cold day, when they were warmed b y the sun, they would buckle and perhaps come loose.If the rails were put down tightly on a hot day, they would pull apart in tank car weather. Either could cause a very serious accident. Expansion and Contraction of Power Lines On a very hot or cold day, locate power lines near your home hanging between two poles or towers. Notice how much the lines sag. Measure and record the temperature as well as the date and time. Select a good spot to take a picture of the lines. Carefully note exactly where you make this picture in your notebook, including any zoom setting and the center of your photo.Make sure that you will be able to return to the exact spot several months from now. run off to the same spot when the weather is much hotter or colder, depending on when you did this the prototypical time. Again, measure and record the temperature, date and time. Take another picture of the wires using the same zoom settings and center point as before. Compare the two pictures. What do you s ee? What HappenedThe wires sagged much less in cold weather. Wire, like all other solids, expands when it is warmed and contracts when it is cooled. In hotter weather, it will expand more, causing the wires to sag more.When power or phone lines are strung, they are ever so sagged to allow for expansion and contraction. If they were to be strung too tight, they could snap when they contract in colder weather. An Exception to Expanding and Contracting in Solids As we have seen, solids commonly expand when heated and contract when cooled. However, some solids dont perpetually behave according to this rule, as this experiment will show. Procedure looseness the box on its side as shown. Place the pushpin in the top edge of the box and hang the rubber eraserise band over the pushpin. (If you cant get the pushpin to hold firmly, try tape the rubber band. Tie a small weight to the other end of the rubber band. The weight should be heavy enough to stretch the rubber band, but not enough to break it. Set the dryer on its hottest setting and heat the rubber band. Note what happens to the rubber band. What Happened or else of expanding as we would have expected, the rubber band contracted and lifted the weight. Molecules of rubber are long and twisted, something like a loose spring. Rubber molecules exhort when they are heated, causing them to draw together like a tighter spring. When all of the molecules do this, the rubber band contracts.