Physical and Chemical Properties/Changes Chemical Properties properties of a substance that can only be observed during a reaction. It always – results in a new substance being formed. (very important to remember.) Flammability does the substance burn – (react with oxygen to release heat)? Reactivity does the substance chemically – combine with other chemicals, such as acids & bases? Rusting does the substance react with oxygen. – Signs that a chemical change has happened: Energy released (a change in temperature up or cools down/light) ex: match burns, cold packs cool gas or bubbles form ex: vinegar + baking soda CO2 permanent unexpected color change ex: burning wood changes its odor released ex: baking bread creates new gases More Evidence of a chemical change: difficult to reverse ex: can’t turn a cookie back into dough Production of a gas ex: vinegar and baking soda produces CO2 Formation of a precipitate ex: vinegar and milk forms curds (cheese) Physical Properties - Characteristics of Matter that can be easily seen through direct observation. A new substance is NOT created. Examples: 1. Elasticity-ability to return to its original shape or size after stretching
Physical and Chemical Properties/Changes Chemical Properties – properties of a substance that can only be observed during a reaction. It always results in a new substance being formed. (very important to remember.) Flammability – does the substance burn (react with oxygen to release heat)? Reactivity – does the substance chemically combine with other chemicals, such as acids & bases? Rusting – does the substance react with oxygen. Signs that a chemical change has happened: Energy released (a change in temperature up or cools down/light) ex: match burns, cold packs cool gas or bubbles form ex: vinegar + baking soda CO2 permanent unexpected color change ex: burning wood changes its odor released ex: baking bread creates new gases More Evidence of a chemical change: difficult to reverse ex: can’t turn a cookie back into dough Production of a gas ex: vinegar and baking soda produces CO2 Formation of a precipitate ex: vinegar and milk forms curds (cheese) Physical Properties - Characteristics of Matter that can be easily seen through direct observation. A new substance is NOT created. Examples: 1. Elasticity-ability to return to its original shape or size after stretching
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