Across
- 7. they react when exposed to air and water but their reactivity is not as strong as that of the alkali metals.
- 10. Are shiny, malleable, ductile and are good conductors
- 12. Takes place when 2 or more substances combine to form new substances.
- 13. Identifies which elements, and how much of each, are in the compound.
- 14. Chemical reaction that absorbs heat energy
- 15. found in many different types of animal and plant cells, speeds up the breakdown of hydrogen peroxide into harmless oxygen and water.
- 16. is the slow chemical change that occurs when oxygen in the air reacts with a metal
- 17. The new materials produced by the reaction
- 20. Meaning to go and wonder
- 21. have both metallic and non-metallic properties.
- 22. Means below
- 23. without these, many reactions would require much higher temperatures- a situation that would be deadly to the human body.
- 24. common example of corrosion- associated with certain metals (;metal gates, car bumpers etc)
Down
- 1. most reactive metals
- 2. Most reactive non-metals
- 3. Are pure substances formed as a result of the attraction between particles of opposite charges
- 4. sodium bicarbonate
- 5. Horizontal row
- 6. meaning 5
- 7. Is measured by atomic mass unit
- 8. They can be solids, liquids, or gases at room temperature, insulators and or poor conductors of electricity
- 9. are substances that help a reaction proceed faster
- 11. The materials at the start of a reacttion
- 18. Most stable elements
- 19. is a chemical reaction that occurs when oxygen reacts with a substance to form a new substance and give off energy.