Across
- 2. a chemical reaction in which two compounds exchange positive ions and form new compounds
- 9. the force that holds atoms or ions together as a unit
- 12. a chemical reaction in which a compound breaks down into two or more simpler substances
- 13. a chemical bond in which two atoms share a pair of valence electrons
- 14. a substance that undergoes change in a chemical reaction
- 16. a representation of a chemical reaction in which the reactants and products are expressed as formulas
- 20. a diagram of an atom, ion or molecule in which each dot represents a valence electron
Down
- 1. a chemical reaction in which one element takes the place of another element in a compound
- 3. numbers that appear before a formula in a chemical equation to show the relative proportions of each reactant and product
- 4. a neutral group of atoms that are joined together by one or more covalent bonds
- 5. a chemical reaction in which two or more substances react to form a single substance
- 6. the energy stored in chemical bonds
- 7. an atom or group of atoms that has a positive or negative charge
- 8. an ion with a positive charge
- 10. notation that shows what elements a compound contains and the ratio of the atoms or ions of these elements in the compound
- 11. an ion with a negative charge
- 15. new substances formed as a result of a chemical reaction
- 17. a mixture of two or more elements, at least one of which is a metal, that has the characteristic properties of a metal
- 18. the force that holds cations and anions together
- 19. the attraction between a metal cation and the shared electrons that surround it