Across
- 3. positively charged particle in the nucleus of an atom
- 6. system an experiment in which all reactants and all products of a chemical reaction are accounted for
- 7. reactions reaction that takes place when two or more substances react to form new substances
- 9. reaction that occurs when oxygen reacts with a substance to form a new substance and give off energy
- 10. compound pure substance formed when at least one metal and one non-metal combine
- 12. substance that helps a chemical reaction to proceed more quickly
- 14. element that has both metallic and non-metallic properties
- 15. 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
- 18. catalyst involved in chemical reactions in living things
- 19. neutral particle in the nucleus of an atom
- 20. number the sum of the number of protons and neutrons in an atom
- 21. number number of protons in the nucleus of one atom of an element
Down
- 1. 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
- 2. ability of a substance to conduct electricity or heat
- 4. compound pure substance formed when non-metals combine
- 5. table table in which the elements are organized by their physical and chemical properties
- 8. dull, brittle element that does not conduct electricity
- 11. group 17 elements in the periodic table;the most reactive non-metals
- 13. metals group 1 elements in the periodic table, not including hydrogen; the most reactive of the metals
- 16. system an experiment in which one or more products of a chemical reaction can escape
- 17. monoxide (CO(g))colourless, odourless gas;produced by incomplete combustion of chemicals containing carbon (e.g. hydrocarbons); major source: motor vehicles