Wk 14,15 Vocab

Spencer lee B 2/17/07 Vocabulary Chapter 14 1. Chemical Bonding- The joining of atoms to form new substances 2. Chemical Bond- A force of attraction that holds two atoms together 3. Theory- A unifying explanation for a broad range of hypotheses and observations that have been supported by testing 4. Valence Electrons- The electrons in the outermost energy level of an atom; these electrons are involved in forming chemical bonds 5. Ionic Bond- The force of attraction between oppositely charged ions 6. Ions- Charged particles that form during chemical changes when one or more valence electron transfer from one atom to another 7. Crystal Lattice- A repeating three-dimensional pattern of ions 8. Covalent Bond- The force of attraction between the nuclei of atoms and the electrons shared by the atoms 9. Molecule- A neutral group of atoms held together by covalent bonds 10. Metallic Bond- The attraction between a positively charged metal ion and the electrons in a metal

Spencer lee B 4/17/07 Vocabulary Chapter 15 1. Chemical Reaction- The process by which one or more substances undergo change to produce one or more different substances 2. Chemical Formula- A shorthand notation for a compound or a diatomic element using chemical symbols and numbers 3. Subscript- A number written below and to the right of a chemical symbol in a formula 4. Chemical Equation- A shorthand description of a chemical reaction using chemical formulas 5. Reactants- The starting materials in a chemical reaction 6. Products- The substances formed from a chemical reaction 7. Coefficient- A number placed in front of a chemical symbol or formula; used to balance a chemical equation 8. Law of Conservation of Mass- The law that states that mass is neither created nor destroyed in ordinary chemical and physical changes 9. Synthesis Reaction- A reaction in which two or more substances combine to form a single compound 10. Decomposition Reaction- A reaction in which a single compound breaks down to form two or more simpler substances 11. Single-replacement Reaction- A reaction in which an element takes the place of an element in a compound; this can occur only when a more-reactive element takes the place of a less-reactive one 12. Double-replacement Reaction- A reaction in which ions in two compounds switch places; one of the products is often a gas or a precipitate 13. Exothermic- The term used to describe a change in which energy is released or removed; the change can be a physical change or chemical change

14. Endothermic- The term used to describe a change in which energy is absorbed; the change can be a physical change or a chemical change 15. Law of Conservation of Energy- The law that states that energy is neither created nor destroyed 16. Activation Energy- The minimum amount of energy needed for substances to react 17. Catalyst- A substance that speeds up a reaction without being permanently changed 18. Inhibitor- A substance that slows down or stops a chemical reaction