The BIG 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     28       29      
           30           31      
32       33                     
    34                35        
      36          37            
  38     39             40   41         
                       42   
 43       44                    
     45                     
46      47          48      49     50       
                        
 51          52    53       54       55     
                        
  56           57               

Across:

1. A universal indicator colour for a very slow reacting weak acid. (6)
4. This means to get the metal from its ore. (7)
7. These react with metals to form a flammable or even explosive gas! (5)
9. A very unreactive gaseous element which is in light bulbs to stop the tungsten filament from burning out. (5)
11. Symbol for the moderately reactive element zinc. (2 but 2nd should be small)
12. The lower the metal is in the 'reactivity series' the (6)? it is to extract it from its compounds or ore.
17. Sodium is kept under this because it is so reactive to oxygen and water. (3)
18. A useful list or order of metals we get from seeing how fast they react with water or acids (10,6)
20. Formed by reacting copper oxide with nitric acid (6,7)
21. When metals are (4)? in the 'series' they react fast!
23. The word describing the type of reaction: zinc + copper sulphate ==> zinc sulphate + copper (12)
25. Water containing universal indicator should be this colour before you add anything to it. (5)
26. A metal that is not very reactive until you do the thermit reaction! (9)
28. The compounds formed when elements burn in oxygen. (6)
30. Symbol for a metal or a deadly gas formed from the incomplete combustion of fuels? (2)
31. The raw material you dig out of the ground to get your metal from. (3)
32. The colour of universal indicator in acids. (3)
33. The costly method of extraction needed to produce very reactive metals. (12)
35. The colour of magnesium oxide. (5)
38. The black compound formed when an orange metal is heated in air. (6,5)
40. The name of the spectacular reaction between iron oxide and the 'greenhouse frame' metal! (7)
43. Its a pity it rusts so easily! (4)
44. The colourful and useful check for the pH of a solution (9,9)
46. The formula of a compound that dissolves in sulphuric acid to forms a blue salt solution with no fizzing! (2, middle letter should be small)
47. This metal burns very brightly with a brilliant white flame. (9)
49. A pretty but unreactive metal found in brass. (6)
51. The more reactive a metal, the more (9)? it is to extract it!
53. The symbol for the metal used for making aircraft frames. (2, 2nd letter should be small)
54. By collecting scrap it (8)? the iron!
56. If a metal is found '(6)' it means it can be found as the pure uncombined metal in rocks.
57. The symbol for an extremely reactive metal, a lot faster than potassium! (2, 2nd letter is small)

Down:

1. The currency you buy your metals with in Japan! (3)
2. Sodium floats on it and fizzes! (5)
3. The symbol of one of the few common magnetic metals. (2, 2nd is small letter)
5. It means the metal surface goes dull from oxidation. (7)
6. Symbol of the metal used in photographic salts, and very pretty in jewellery. (2, 2nd letter is small)
8. Type of compound formed when a metal oxide, hydroxide or carbonate reacts with an acid. (4)
10. Symbol of metal that burns with a bright yellow-orange flame. (2, 2nd letter is small)
13. The physical description of copper oxide. (5,5)
14. The final universal indicator colour when sodium has finished reacting with water! (6, not violet)
15. Salt formed when magnesium carbonate dissolves in hydrochloric acid (9,8)
16. Symbol for the metal titanium used in steels. (2, 2nd letter is small)
17. The reactive part of air that corrodes metals! (6)
19. The colour of the coating you get on copper when its dipped in silver nitrate solution! (6)
22. A metal used in batteries and to galvanise iron or steel to stop them rusting. (4)
24. Type of British sports car or a metal symbol? (2, 2nd letter is small)
27. Used as yellow money!!!!! (4)
29. You do NOT put this soft metal in acid!!!! (6, and NOT cesium!)
30. The symbol for a metal or the deadly gas formed by inefficient burning of fuels. (2)
32. An orange-brown powder, such a waste of iron! (4)
34. The call-sign of a well known gas next to a lit splint!! (3)
36. Education after school or symbol of a well known metal? (2, 2nd letter is small)
37. A word describing the chemical reduction process of changing a metal compound into the metal eg in a blast furnace. (8)
38. Copper roofs turning green are an example of this type of process. (9)
39. Chemical symbol of the first metal used by the Romans in their plumbing! (2, 2nd letter is small)
41. The gas formed when metals react with acids or water. (8)
42. These in cans are acidic and cause corrosion. (6)
45. Symbol for quite a reactive metal or California? (2, 2nd letter is small)
48. Sodium does this as it floats and reacts with water. (5)
50. I hope this high for the wages of minors working in their dangerous environment! (3)
52. A useful metal, once got from Cornwall, used to coat the inside of steel food cans to stop rusting. (3)
55. When metals are (3)? in the reactivity series they are usually easier to extract.