The SMALL crossword on "PATTERNS of REACTIVITY" @ doc brown's chemistry

FOR PRINTING OUT ONLY, answers found via KS3 chemistry link above
          1            
2        3           4       
5                6        
                    
   7            8         
9                      
        10    11            
  12   13    14                 
                    
  15               16       
              17        
        18      19          
20                   21     
                    
  22                    
                    
          23   24        25    26   
                    
                    
   27                   

Across:

5. The costly method of extraction needed to produce very reactive metals. (12)
6. Sodium does this as it floats and reacts with water. (5)
7. The compounds formed when elements burn in oxygen. (6)
8. The reactive part of air that corrodes metals! (6)
9. A useful metal, once got from Cornwall, used to coat the inside of steel food cans to stop rusting. (3)
10. The physical description of copper oxide. (5,5)
12. The final universal indicator colour when sodium has finished reacting with water! (6, not violet)
15. The word describing the type of reaction: zinc + copper sulphate ==> zinc sulphate + copper (12)
17. You do NOT put this soft metal in acid!!!! (6, and NOT cesium!)
20. This means to get the metal from its ore. (7)
22. Salt formed when magnesium carbonate dissolves in hydrochloric acid (9,8)
23. Its a pity it rusts so easily! (4)
25. Sodium is kept under this because it is so reactive to oxygen and water. (3)
27. Formed by reacting copper oxide with nitric acid (6,7)

Down:

1. These react with metals to form a flammable or even explosive gas! (5)
2. A useful list or order of metals we get from seeing how fast they react with water or acids (10,6)
3. Used as yellow money!!!!! (4)
4. Collecting scrap iron and steel is to (7)? a useful metal.
11. A metal that is not very reactive until you do the thermit reaction! (9)
13. An indicator for every solution? (9)
14. The call-sign of a well known gas next to a lit splint!! (3)
16. The black compound formed when an orange metal is heated in air. (6,5)
18. Storing this in cans leads to corrosion unless the tin is coated!
19. When metals are (4)? in the 'series' they react fast!
21. The gas formed when metals react with acids or water. (8)
24. An orange-brown powder, such a waste of iron! (4)
26. When metals are (3)? in the reactivity series they are usually easier to extract.