Presentation on theme: "Chemical Changes. Learning Intentions… … that Bunsen burners are used to heat materials. … to adjust Bunsen burner flames, and choose the right one."— Presentation transcript:
Learning Intentions… … that Bunsen burners are used to heat materials. … to adjust Bunsen burner flames, and choose the right one for heating. … to use a flame test to find out what is in a powder. … to be careful when using gas.
1. Put on your safety glasses. 2. Place the Bunsen burner on a heat-proof mat. 3. Push the rubber tube onto the gas tap. 4. ALMOST CLOSE the air hole. 5. Hold a lighted splint over the top of the Bunsen burner – about 2 cm above. 6. Turn on the gas tap slowly.
Name of SubstanceColour of Flame Lithium Calcium Barium Potassium Sodium Substance X
Learning Intentions… … to describe what happens when some materials are heated or cooled. … that heating or cooling some substances can cause them to change. … to understand the idea of reversible changes. … to distinguish between reversible and irreversible changes.
Learning Intentions… … that some substances are soluble and others are insoluble. … that insoluble substances can be separated by filtering. … that soluble substances can be recovered by evaporation … to understand that these changes are reversible. … to develop the idea of sizes of particles, and use this to explain why different methods of separation are needed. … to appreciate the healing effects of medicines. … to determine a ‘best buy’ for a specific product.
Dissolving things – some definitions If a substance CAN be dissolved it is called __________ If a substance CANNOT be dissolved it is called _________ Words – soluble, solute, solvent, solution, insoluble
Solubility words Solute Solution Solvent Saturated Solubility How much of something that can be dissolved is called… A solution that CAN’T dissolve anything else is… The solid that will be dissolved is the… The mixture of solute and solvent is called the… The liquid that the solute will be dissolved into is the…
Learning Intentions… … that school science can be related to jobs in the outside world …to plan a scientific investigation. … to carry out a scientific investigation .… to report on a scientific investigation.
Learning Intentions… … that when materials burn a flame can be seen. … that heat causes chemical changes. … that in chemical changes new substances are formed, some of which may be invisible. … that safety is essential when heating or burning materials.
Another word for burning is….. M C O B U S T I O N COMBUSTION
Learning Intentions… … that fire happens when a material burns. … that fire needs oxygen, fuel and heat energy, and that fires can be put out by removing one of these essential things. … that fire under control can be very useful, but we need protection from its harmful effects. … that, as responsible young people, we can protect our environment from fire devastation.
Fuels Fuels are substances that can be used to release useful amounts of energy when they burn, e.g. Oil Gas Wood
Burning things When something is burned it reacts with oxygen. For example: Magnesium + oxygen Magnesium oxide Carbon + oxygen Carbon dioxide Sulphur + oxygen Sulphur dioxide The Fire Triangle Fire Fuel Oxygen Heat