Across
- 1. cloudy mixture in which tiny particles of one substance are held within another and particles cannot be separated out from the other substance
- 4. process in which molecules move from an area of higher concentration to one of lower concentration
- 7. with a pH lower than 7
- 9. (CO(g)) colourless, odourless gas; produced by incomplete combustion of chemicals containing carbon (e.g. hydrocarbons); major source: motor vehicles
- 15. a reaction that takes place when two or more substances react to form new substances
- 20. chemical reaction that absorbs energy
- 21. amount of mass in a given volume of a substance
- 23. combination of symbols that represent a compound; the formula identifies the elements in the compound and the amount of each element
- 24. the smallest part of an element that is representative of that element; a neutral particle made up of a nucleus containing protons and neutrons, and in which the number of electrons equals the number of protons
- 26. principle that matter is not created or destroyed in a chemical reaction; the mass of the products always equals the mass of the reactants
- 28. catalyst involved in chemical reactions in living things
- 29. change of state from a gas to a liquid
Down
- 2. description of a solid that can be stretched into a long wire
- 3. slow chemical change that occurs when oxygen in the air reacts with a metal
- 5. group 1 elements in the periodic table,not including hydrogen; the most reactive of the metals
- 6. energy stored in chemicals and released when chemicals react; a form of potential or stored energy
- 8. compound that dissolves in water to form a
- 10. mass of one atom of an element calculated from the total number of protons, neutrons, and electrons of that atom; measured in atomic mass units (amu)
- 11. change that results when two or more substances react to create a different substance or substances; the new substances have completely different properties from the original ones
- 12. description of how a substance interacts with other substances, such as acids; chemical properties are observable only when a chemical change occurs
- 13. a solution in which water is the solvent
- 14. group 2 elements in the periodic table; their reactivity is not as strong as that of the alkali metals
- 16. chemical reaction that takes place in cells; food (sugar) reacts with oxygen to produce energy, water, and carbon dioxide
- 17. chemical combination of two or more elements in a specific ratio
- 18. number of protons in the nucleus of one atom of an element
- 19. measure of atomic mass; 1 amu is equal to 1/12th the mass of a carbon 12 atom
- 22. chemical reaction that occurs when oxygen reacts with a substance to form a new substance and give off energy
- 23. substance that helps a chemical reaction to proceed more quickly
- 25. an experiment in which all reactants and all products of a chemical reaction are accounted for
- 27. invisible negatively charged particle that orbits the nucleus of an atom