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Science vocab
chemistry
Term | Definition |
---|---|
Phisical change | A change tjat alters the form or apperance 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 substance |
Reactant | A substance that enters into 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 consevations of mass | The priciple that the total amount of matter is neither created nor destoyed 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 elements 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 mateeial 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 |