Word | Definition |
matter | anything that has mass and takes up space |
chemistry | the study of the properties of matter and how it changes |
physical property | a characteristic of a substance that can be observed without changing the substance into another (color, hardness, texture, shine, flexibility) |
chemical property | a characteristic of a substance that descibes its ability to change into other substances (burning, rusting, tarnishing) |
physical change | a change that distorts the form or appearance of a substance without changing it into another substance |
chemical reaction | a change in matter that produces more new substances |
precipitate | a solid that forms during a chemical reaction |
endothermic reaction | a reaction that absorbs energy in the form of heat |
exothermic reaction | a reaction that releases energy in the form of heat |
chemical equation | a short, easy way to show a chemical reaction |
reactant(s) | the substance(s) you have before a chemical reaction |
product(s) | he substance(s) you have at the end of a chemical reaction |
conservation of mass | during a chemical reaction, matter is not created or destroyed, just rearranged |
open system | a system in which matter can enter from or escape into its surroundings |
closed system | a system in which matter can't enter or leave |
coefficient | a number placed in front of a chemical formula in an equation, it multiplies the formula by that number |
synthesis | 2 or more elements combine |
decomposition | breaks down compounds |
replacement | elements rearrange and trade places |
actavation energy | the minimum energy needed to start a chemical reaction |
concentration | the amount of a substance in a given volume |
catalyst | a material that increases the rate of a reaction by lowering the activation energy |
enzymes | biological catalysts that lower actavation energy in cells |
inhibitor | decreases the rate of a reaction by preventing reactants from coming together |
combustion | a rapid reaction between oxygen and a fuel |
fuel | a material that releases energy when it burns
ie)oil, wood, gas, paper |