Complete the crossword, then click on "Check" to check your answer. If you are stuck, you can click on "Hint" to get a free letter. Click on a number in the grid to see the clue or clues for that number. All the best. Dr E

 

					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

 Check 

Across: 2. A description of iron which has reacted with oxygen and water. 6. The smallest possible particle of matter. 8. The commonest oxide on earth. 9. 8 across is made of this type of particle. 11. Opposite of OFF. 12. Seed of a legume 13. This element burns with a bright white flame. 16. A charged particle. 17. and 4 down. Sulphur and carbon are examples of this category of elements. 18. The commonest gas in air. 21. An element used in making pipes and electrical wires. 23. A prefix meaning opposite. 25. A substance which contains only a single type of atom. 27. All substances have this property which resists acceleration. 28. A chemist performs a ____ to find out what a substance is made of. 31. This tool was made during the 33 across age. 33. This element is used in making ships and bridges 35. Proceed. 37. Large black member of the cat family 39. A pair is required for kissing 40. The chloride of this metal is used to flavour chips. 41. Acts which are against the law. 42. See 4 down. 43. The element with the smallest and lightest atom. 45. Abbreviation for Atomic Mass Unit 47. Neither .... 48. This gaseous element is used to kill bacteria during water purification.

Down: 1. Formula for 8 across. 2. Regret French street. 3. Beautiful knock out. 4. and 42 across. Gas produced during respiration. 5. See 17 across. 6. A metal with low density and a very good electrical conductor. 7. The gas required for respiration. 10. A pure substance containing two (or more) atoms chemically combined. 14. Flavouring from the east. 15. The metal used to galvanise steel to prevent it from rusting. 19. The unreactive gas which fills light bulbs. 20. Opposite of East. 22. A mineral from which a metal can be extracted economically. 24. A prefix to a unit meaning 0.000 000 001. 26. Air is an example, a substance containing two or more elements or compounds which are not chemically combined. 29. Thin pieces (chips) of this element are used to make the central processing unit of a computer. 30. Remove a small amount (of hair). 32. An element which exists as a yellow solid at room conditions. 34. A tool used to take the top off a tin of beans. 35. A yellow coloured (precious) metal. 36. A teacher. 38. A category of substance which gives a sour taste. 40. (Almost) pure carbon found in chimneys. 44. Sticky mess. 45. Chemical symbol for 6 down. 46. Chemical symbol for molybdenum.