| A | B |
|---|
| Atom. | the smallest piece of matter that still retains the property of the element. |
| Chemical reaction. | process that produces chemical change,resulting in new substances that have properties different from those of the original substances. |
| Reactants. | substance that exists before a chemical reaction begins. |
| Products. | substance that forms as a result of a chemical reaction. |
| Chemical equation. | shorthand form for writing what reactants are used and what products are formed in a chemical reaction;sometimes shows whether energy is produced or absorbed. |
| Endothermic reaction. | chemical reaction in which energy is absorbed. |
| Exothermic reaction. | chemical reaction in which heat energy is released. |
| State of matter. | physical property that is dependent on temperature and pressure and occurs in four forms - solid,liquid,gas,or plasma. |
| Activation energy. | minimum amount of energy needed to start a chemical reaction. |
| Rate of reaction. | measure of how fast a chemical reaction occurs. |
| Concentration. | describes how much solute is present in a solution compared to the amunt of the solvent. |
| Inhibitor. | is a substance that slows down a chemical reaction,making the formation of a certain amount of product take longer. |
| Catalyst. | is a substance that speeds up a chemical reaction but is not used up itself or permanently changed. |
| Enzymes. | are large protein molecules that speed up reactions needed for your cells to work properly.They help your body convert food to fuel. |
| Figure 4. | The law of conservation of states,that the number and kind of atoms must be equal for products and reactants. |
| Heat Absorved. | some chemical reactions and physical processes need to have heat energy,before they can proceed. |
| Figure 12. | Most fuels need energy to ignite.. |
| Figure 15. | Molecules collide more frequently at higer temperatures than at lower temperatures.This means they are more likely to react. |
