Chemistry is a basic science whose central concerns are: 1. The structure and behaviour of atoms (elements) 2. The composition and properties of compounds 3. The reactions between substances with their accompanying energy exchange 4. The laws that unite these phenomena into a comprehensive system.     (len92)		Pour 1 cm of oil (olive or sesame) on top of 3/4 cup of cold water.  Then sprinkle some salt on the oil surface. Oil is less dense than water, so it floats. Salt is more dense than both water and oil so it sinks. What makes things interesting in this trick is that the oil tends to cling to the salt temporarily. Together, the oil and salt blobs are denser than water, so they descend to the bottom of the cup. As the blobs go down, the oil coats and protects the salt from dissolving. However, after it sinks, the oil soon yanks free from the salt and rises again.
Floating Egg Lower a raw egg into 1/4 cup of water.  Stir several tablespoons of salt into the water and watch the egg rise.  The egg is salty water floats because the weight of the salt water it displaces is greater than the weight of the egg.  Carefully spoon fresh water on top and the egg will float between the layers.	Chromatography Mix red and blue food coloring together. Place some mixed drops on strips of coffee filter or white napkins. Suspend the stained filter papers in water and watch the colors separate. The water acts as a solvent and because the colors dissolve at different rates, the colors should separate into purple (red-blue) and light blue areas. You may try different combinations of food colors - caused by capillary action.	Poor Man's Lava Lamp Pour a few raisins into a glass of club soda (loaded with carbon dioxide) The raisins will rise to the top as they pick up bubbles of CO2 and will drop as the bubbles burst - then the cycle will repeat again.
Food Coloring on Milk 1) Pour a thin (0.5 cm) deep layer of milk into the bottom of the pie plate 2)Add drops of food colouring and observe. 3) Add one large drop of dishwashing liquid near the centre and observe. Prior to adding the dishwashing liquid, the food colouring stays together in "splotches" of colour. This is in contrast to water, where the food colouring quickly dissipates throughout the liquid (this is a good experiment to run at the same time!). The reason behind this is that milk is not a simple liquid like water, but a colloidal suspension of fat and protein molecules. The soap breaks the surface tension of the water and the soap skates to the edges of the container.	Make Plastic With Milk Place milk in saucepan and warm on stove to skin temperature (about 37°:C). Add vinegar or lemon juice while stirring. The milk will quickly coagulate. Roll out mass on a sheet of aluminium foil or a cutting board.  Drain excess liquid. Let the resulting "plastic" sheet dry overnight. The globules in milk are a combination of fat and protein. The protein is bound up in tight coils, through internal "bonding" - electronic interactions between adjacent atoms. Vinegar and lemon juice are both mild acids (they contain acetic acid and citric acid, respectively) and they are capable of "denaturing" the proteins in the milk globules. What this means is that they are capable of prying the molecules open and breaking some of the internal bonds that hold the atoms to each other.	Green Slime The polymers cellulose and starch are naturally occurring polymers made from glucose residues. That is, they are composed of a long chain of glucose molecules strung together like the beads on a necklace.   Starch is found in a variety of grains and corn. It is a structural fibre for many plants. And it has some interesting properties. Starch is used in cooking to "thicken" sauces and glazes. It can cross link, when heated, to form a much more complicated polymer which provides a three dimensional matrix. A box of cornstarch and a cup of water can be used to demonstrate molecular motion or the lack thereof. Simply mix the two together in a large container. The resulting "slime", "magic mud", "goo" is very viscous. That is, the molecules involved do not slip past each other quickly. This is a consequence of their size. Starch molecules - each is a chain of thousands of atoms joined together by very strong bonds. And this makes it difficult for the molecules to move quickly. The consequence of this is that when struck a sharp blow, the "magic mud" appears to behave as a solid surface. It is difficult to do more than dent the surface slightly. However, if an object or finger is pressed into the "magic mud" slowly, the molecules have time to move out of the way allowing for penetration. Similarly, if a handful is squeezed, it will retain its shape for a short period of time as the molecules only slowly move past one another to allow the "magic mud" to flow.
MAKE A VOLCANO Take a 500 mL bottle, a cup of vinegar and a cup of baking soda and the  whites of two eggs. Mix the baking soda and egg whites together. Place in container then add vinegar. The bubbling that results from the reaction of baking soda and vinegar is the carbon dioxide produced by the chemical reaction that is occurring. Baking soda is a chemical substance called "sodium carbonate" and it is the carbonate that is reacting with the acid to give the gaseous carbon dioxide. Because gases occupy more volume than solids, an expansion occurs. The egg white contains proteins that are denatured by the acid. That is, they unfold and seek out new partners. As they do this, they form a "meringue" which is a little more solid and substantial than the bubbles that normally form with just baking soda and vinegar, although it is still created by the carbon dioxide released as the carbonate reacts. With the right proportions, the resulting "lava" will have a substantially longer lifespan.	FIREPROOF A BALLOON Inflate one of two balloons and tie it closed. Place 60 milliliters (¼ cup) of water in the other balloon, and then inflate it and tie it shut. Light a match and hold it under the first balloon. Allow the flame to touch the balloon. What happens? The balloon breaks, perhaps even before the flame touches it. Light another match. Hold it directly under the water in the second balloon. Allow the flame to touch the balloon. What happens with this balloon? The balloon doesn't break. You may even see a black patch of soot form on the outside of the balloon above the flame. Why does the balloon with no water break in the flame? The flame heats whatever is placed in it. It heats the rubber of both balloons. The rubber of the balloon without water becomes so hot, that it becomes too weak to resist the pressure of the air inside the balloon. How does the balloon with water in it resist breaking in the flame? When water inside the balloon is placed in the flame, the water absorbs most of the heat from the flame. Then, the rubber of the balloon does not become very hot. Because the rubber does not become hot, it does not weaken, and the balloon does not break. Water is a particularly good absorber of heat. It takes a lot of heat to change the temperature of water. It takes ten times as much heat to raise the temperature of 1 gram of water by 1C than it does to raise the temperature of 1 gram of iron by the same amount. This is why it takes so long to bring a teakettle of water to the boil. On the other hand, when water cools, it releases a great deal of heat. This is why areas near oceans or other large bodies of water do not get a cold in winter as areas at the same latitude further inland.	RED CABBAGE JUICE INDICATOR approx pH: 2 4 6 8 10 12 color of extract red purple violet blue blue- green green Test vinegar, laundry ammonia, baking soda (mixed with water) soft drinks,  lemon juice, sugar, salt, shampoo, hair rinse, milk of magnesia, antacid tablets, and aspirin.
MILK AND A BLUE SKY You'll need a flashlight, a large  container of water (aquarium) and a  glass of milk.   When you added milk to the water, you added many tiny particles to the water. Milk contains many tiny particles of protein and fat suspended in water. These particles scatter the light and make the beam of the flashlight visible from the side. Different colors of light are scattered by different amounts. Blue light is scattered much more than orange or red light. Because we see the scattered light from the side of the beam, and blue light is scattered more, the beam appears blue from the side. Because the orange and red light is scattered less, more orange and red light travels in a straight line from the flashlight. When you look directly into the beam of the flashlight, it looks orange or red.	What does this experiment have to do with blue sky and orange sunsets? The light you see when you look at the sky is sunlight that is scattered by particles of dust in the atmosphere. If there were no scattering, and all of the light travelled straight from the sun to the earth, the sky would look dark as it does at night. The sunlight is scattered by the dust particles in the same way as the light from the flashlight is scattered by particles in milk in this experiment. Looking at the sky is like looking at the flashlight beam from the side: you're looking at scattered light that is blue. When you look at the setting sun, it's like looking directly into the beam from the flashlight: you're seeing the light that isn't scattered, namely orange and red. What causes the sun to appear deep orange or even red at sunset or sunrise? At sunset or sunrise, the sunlight we observe has traveled a longer path through the atmosphere than the sunlight we see at noon. Therefore, there is more scattering, and nearly all of the light direct from the sun is red.
REMOVING SILVER SULPHIDE Line the bottom of a metal pan with aluminium foil. Set the silver object on top of the aluminium foil. Make sure the silver touches the aluminium. Heat the water to boiling. Remove it from the heat and place it in a sink. To the hot water, add about one cup of baking soda for each gallon of water. (If you need only half a gallon of water, use half a cup of baking soda.) The mixture will froth a bit and may spill over; this is why you put it in the sink. Pour the hot baking soda and water mixture into the pan, and completely cover the silver. When silver tarnishes, it combines with sulphur and forms silver sulphide. Silver sulphide is black. When a thin coating of silver sulphide forms on the surface of silver, it darkens the silver. The silver can be returned to its former lustre by removing the silver sulphide coating from the surface. The tarnish-removal method used in this experiment uses a chemical reaction to convert the silver sulphide back into silver. This does not remove any of the silver. Many metals in addition to silver form compounds with sulphur. Some of them have a greater affinity for sulphur than silver does. Aluminums is such a metal. In this experiment, the silver sulphide reacts with aluminums. In the reaction, sulphur atoms are transferred from silver to aluminums, freeing the silver metal and forming aluminums sulphide. Chemists represent this reaction with a chemical equation.	CHROMATOGRAPHY EXPERIMENT Link 2  Link 3  Link 4  Link 5  Link 6 Most things we encounter in our lives are mixtures of different substances. Very few things consist of a single substance.  For example, a perfume may consist of hundreds of different substances, each one of which can influence the overall smell of it. Chromatography is a method used to separate mixtures. This is important because if we can separate a mixture then we can measure how much there is of each substance. It also allows us to identify those substances and to isolate them for further study. If you have carried out a paper chromatography experiment you may have applied some colour from a felt tipped pen or an extract from a plant leaf near the bottom of a strip of paper and suspended the end of the strip in water. As the water rose up the paper strip the mark you applied appeared to spread upwards and other colours appeared In our experiment we will try to identify 5 mystery dyes:  Chartreuse - 12 drops of yellow food  colouring and 1 drop of green Turquoise - 5 drops of blue and 1 drop of green food colouring  M & Ms - stains of red or other coloured  M and Ms. Purple Saurus Rex - stains of Kool Aid  mix Orange Kool Aid Mix - stains of orange  Kool Aid
		Experiments For Home