click below
click below
Normal Size Small Size show me how
Chemical Reactions
Term | Definition |
---|---|
physical change | A change that alters the form or appearance of a material but doe not make the material into another substance. |
Chemical change | A change in which one or more substances combine or break apart to form new substances. |
reactant | A substance that enters into a chemical reaction. |
product | A substance formed as a result of a chemical reaction. |
precipitate | A solid that forms from a solution during a chemical reaction. |
exothermic reaction | A reaction that releases energy, usually in the form of heat. |
endothermic reaction | A reaction that absorbs energy. |
Chemical equation | A short, easy way to show a chemical reaction, using symbols. |
law of conservation of mass | The principle that the total amount of matter is neither created nor destroyed during any chemical or physical change. |
open system | A system in which matter can enter from of escape to the surroundings. |
closed system | a material that decreases the rate of a reaction |
coefficient | A number in front of a chemical formula in an equation that indicates how many molecules or atoms of each reactant and product are involved in a reaction |
synthesis | a chemical reaction in which two or more simple substances combine to form a new, more complex substance |
decomposition | a chemical reaction that breaks down compounds into simpler products |
replacement | A reaction in which one element replaces another in a compound or when two elements in different compounds trade places |
activation energy | the minimum amount of energy needed to start a chemical reaction |
concentration | the amount of one material in a certain volume of another material |
catalyst | a material that increases the rate of a reaction by lowering the activation energy |
enzyme | a type of protein that speeds up a chemical reaction in a living thing; a biological catalyst that lowers the activation energy of reactions in cells |
inhibiter | a material that decreases the rate of a reaction |