| A | B |
|---|
| Matter | Anything that has mass and takes up space |
| Chemistry | The study of the properties of matter and how matter changes |
| Element | A substance that cannot be broken down into any other substances by chemical or physical means |
| Compound | A substance made of two or more elements chemically combined in a specific ration, or proportion. (ex: mineral) |
| Mixture | Two or more pure substances (elements and/or compounds) that are in the same place but not chemically combined. (ex: rock) |
| Solution | A well-mixed mixture. (ex: steel) |
| Physical change | A change that alters the form or appearance of a material but does not convert the material into new substances. (ex: freezing of water, tearing of paper) |
| Chemical change | A change in matter that forms one or more substances. (ex: sedimentary rock melting and recrystallizing to form igneous rock, paper burning to form carbon) |
| Precipitate | A solid that forms from solution during a chemical reaction (ex: minerals such as halite and calcite) |
| Molecule | A particle made up of two or more atoms bonded together. |
| Chemical bond | The force that holds atoms together. |
| Chemical formula | A combination of symbols that represent the elements in a compound. |
| Subscripts | The number of atoms of an element in a molecule or the ratio of elements in a compound written slightly below and to the right of the element symbol. (H2O) The 2 is a subscript |
| Synthesis | A type of chemical reaction where two or more elements combine to form a more complex substance as in photosynthesis. |
| Decomposition | A type of chemical reaction that breaks down complex compounds into simpler products like hydrogen peroxide decomposing into water and oxygen. |
| Replacement | A type of reaction where one element replaces another in a compound (single replacement) or when two elements in different compounds trade places (double replacement). |
| Exothermic reaction | A reaction that releases energy in the form of heat. (feels hot) |
| Endothermic reaction | A reaction that absorbs heat energy. (feels cold) |
| Activation Energy | The minimum amount of energy needed to start a chemical reaction. |
| Concentration | The amount of material in a given volume of another material. (ex: sugar dissolved in water) Increases reaction rate |
| Surface Area | The surface of a substance that may come in contact with another reactant. Increases reaction rate. |
| Temperature | The measure of the average kinetic energy of the particles in a sample of matter. Increases reaction rate |
| Catalysts | A material that increases the rate of a chemical reaction by lowering the activation energy. |
| Inhibitors | A material that decreases the rate of a chemical reaction |
| Enzymes | Biological catalysts that safely increase the rates of chemical reactions necessary to sustain life. |
| Combustion | A rapid reaction between oxygen and a fuel |
| Fuel | A material that releases energy when it burns |
| Fire Triangle | Three things necessary to start and maintain a fire- fuel, oxygen, and heat |
