Across
- 3. a reaction that takes place when two or more substances react to for
- 5. the sum of the number of protons and neutrons in an atom
- 6. metals that have a density of 5 or higher (e.g., copper, zinc, lead, mercury, cadmium,nickel); heavy metals are one type of substance monitored to determine water quality
- 8. 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. ability to do work
- 14. group 2 elements in the periodic table; their reactivity is not as strong as that of the alkali metals.
- 16. group 17 elements in the periodic table;the most reactive non-metals
- 19. combination of symbols that represent a compound; the formula identifies the elements in the compound and the amount of each element
- 20. stance that helps a chemical reaction to proceed more quickly
- 21. chemical combination of two or more elements in a specific ratio
- 22. group 1 elements in the periodic table, not including hydrogen; the most reactive of the metals
- 23. pure substance formed when at least one metal and one non-metal combine
- 25. ability of a substance to conduct electricity or heat
- 26. slow chemical change that occurs when oxygen in the air reacts with a metal
Down
- 1. major source: motor vehicles
- 2. pure substance that cannot be broken down into other substances; substance made up of only one type of atom
- 4. compounds whose molecules do not contain carbon, also included as inorganic compounds are carbon dioxide, carbon monoxide, carbonates, and cyanides
- 7. catalyst involved in chemical reactions in living things
- 9. 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)
- 10. chemial reaction that absorbs energy
- 11. description of how a substance interacts with other substances, such as acids;chemical properties are observable only when a chemical change occurs
- 13. an experiment in which all reactants and all products of a chemical reaction are accounted for
- 15. combustion chemical reaction that occurs when oxygen reacts with a substance to form a new substance and give off energy
- 17. (COg) colourless, odourless gas;produced by incomplete combustion of chemicals containing carbon (e.g.
- 18. number of protons in the nucleus of one atom of an element
- 24. atom that has become electrically charged because it has lost or gained electrons; a positive ion is an atom that has lost one or more electrons;a negative ion is an atom that has gained one or more electrons