Presentation on theme: "Chemical Properties A property of matter which changes the matters identity (composition) when it is observed. Another way to say this is, the matters."— Presentation transcript:
Chemical Properties A property of matter which changes the matters identity (composition) when it is observed. Another way to say this is, the matters composition (identity) changes while testing a chemical property.
If a person burns something, say a wooden baseball bat,… …it would not be a wooden baseball bat, or even wood anymore. Its identity would change and new substances would be created. (ash and smoke)
Examples of Chemical Properties Flammability (ability to be burned) Reactivity (has a chemical reaction with other substances) –Rust on steel (reaction with oxygen) –Tarnish on silver or copper (reaction with oxygen) –Corrosion on a battery –Soured milk –Vinegar reacting with baking soda (produces carbon dioxide)
Signs of Chemical Changes New substance created Change in odor Change in color Fizzing and foaming Production of heat, sound, light or electrical energy Requires heat, sound, electrical or light energy Not easily reversible
Chemical Property –vs.- Chemical Change A chemical property describes what a substance might be able to do… …a chemical change is when it is actually happening.
Examples of Properties vs. Changes A substance may be flammable. (Chemical Property) Burning a piece of paper. (Chemical Change)
A substance may be reactive to acid. (Chemical Property) Baking soda bubbling and foaming when vinegar is placed on it. (Chemical Change)
pH scale Scientists describe a substances acidity using a scale called the pH scale. The scale ranges from zero to 14. 7 is in the middle and is considered neutral. A substance that is very acidic, like battery acid, will be found near the zero end. A substance that is very alkaline, like lye soap, will be found near the 14 end.