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Vocab
Vocabulary words
Term | Definition |
---|---|
Physical change | A change that alters the form or appearance of a material but does 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 |
Exothemic 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 or escape to the surroundings |
Closed system | A system in which no matter is allowed to enter or leave |
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 |
Inhibitor | A material that decreases the rate of a reaction |