1 00:00:29,000 --> 00:00:31,913 Look around you. 2 00:00:39,120 --> 00:00:41,191 Look around you. 3 00:00:47,640 --> 00:00:50,599 Just look around you. 4 00:00:56,080 --> 00:00:58,470 Have you worked out what we're looking for? 5 00:01:01,600 --> 00:01:03,910 Correct. The answer is... 6 00:01:10,400 --> 00:01:12,119 This programme, "Iron", 7 00:01:12,280 --> 00:01:14,431 is discussed in chapter 3 of your textbook, 8 00:01:14,600 --> 00:01:16,751 which accompanies this series. 9 00:01:19,080 --> 00:01:21,470 Please ensure that you have your copybook at hand, 10 00:01:21,640 --> 00:01:24,155 as you'll be asked to take notes down from the screen 11 00:01:24,320 --> 00:01:26,789 at various points throughout the programme. 12 00:01:29,440 --> 00:01:32,672 Iron, or to give it its full name, Iron De Havilland, 13 00:01:32,840 --> 00:01:36,390 is one of the sturdiest and heaviest of all elements. 14 00:01:36,560 --> 00:01:38,040 (CRASH) 15 00:01:38,400 --> 00:01:42,394 This is thanks largely to its rigid molecular structure. 16 00:01:44,440 --> 00:01:47,353 Here is a model of an iron molecule. 17 00:01:48,880 --> 00:01:51,679 And here is a model of a model of an iron molecule, 18 00:01:51,840 --> 00:01:53,957 modelled in iron. 19 00:01:55,360 --> 00:01:58,319 Man has been using iron since the Stone Age, 20 00:01:58,480 --> 00:02:02,599 and over the years, we've garnered a healthy respect for the metal, 21 00:02:02,760 --> 00:02:04,831 so that Sundays are now devoted 22 00:02:05,000 --> 00:02:08,676 to the cleaning and polishing of all our iron possessions. 23 00:02:13,320 --> 00:02:15,312 But it's not all work. 24 00:02:15,480 --> 00:02:19,759 As a young child, you may have played with iron filings, 25 00:02:19,920 --> 00:02:22,515 counting and recounting them over and over again, 26 00:02:22,680 --> 00:02:27,197 and keeping a daily record of the figures in your iron diary. 27 00:02:27,360 --> 00:02:30,432 Some of you may even have tried bending an iron spoon 28 00:02:30,600 --> 00:02:33,399 using nothing but the powers of your imagination. 29 00:02:33,560 --> 00:02:36,553 It rarely works, but it's fun, and that's what counts. 30 00:02:38,080 --> 00:02:40,879 Of course, it's hard to know what De Havilland himself, 31 00:02:41,040 --> 00:02:44,238 the father of iron chemistry, would make of all this, 32 00:02:44,400 --> 00:02:47,791 but no doubt he'd probably have a twinkle in his eye. 33 00:02:56,040 --> 00:02:58,032 An experiment was carried out 34 00:02:58,200 --> 00:03:02,080 to demonstrate the effects of sulphuric acid upon iron. 35 00:03:03,600 --> 00:03:07,480 First, a sample of iron is placed upon a Ravenscroft pan. 36 00:03:07,640 --> 00:03:09,199 (CRASH) 37 00:03:15,240 --> 00:03:19,792 Next, a small quantity of sulphuric acid is collected, via a pipette. 38 00:03:26,200 --> 00:03:30,114 The bell is sounded and the experiment can begin. 39 00:03:31,080 --> 00:03:34,710 The scientist releases a tiny drop of acid onto the iron, 40 00:03:34,880 --> 00:03:39,477 probably only about point point five point 05 microgallons. 41 00:03:39,640 --> 00:03:43,111 Observe the reaction and note down the results in your copybook. 42 00:03:55,280 --> 00:04:00,639 The sulphuric acid has broken the iron into its most basic form, 43 00:04:00,800 --> 00:04:03,918 brown iron, or Bumcivilian. 44 00:04:06,640 --> 00:04:10,873 Now watch what happens when the scientist rings the bell this time. 45 00:04:11,520 --> 00:04:13,512 (SILENCE) 46 00:04:13,880 --> 00:04:16,679 The bell's not broken, it's in good working order. 47 00:04:16,840 --> 00:04:20,197 It's just that when Bumcivilian is produced, 48 00:04:20,360 --> 00:04:24,718 it has the effect of sucking in all the sound from its vicinity. 49 00:04:24,880 --> 00:04:27,236 Even with the scientist joining in, 50 00:04:27,400 --> 00:04:29,392 we still hear nothing. 51 00:04:30,880 --> 00:04:34,715 But after a few seconds, the effect diminishes. 52 00:04:34,880 --> 00:04:38,078 (SCIENTIST SHOUTS, BELL RINGS) 53 00:04:45,720 --> 00:04:49,794 Let's take a look at some of the ways iron is used. 54 00:04:50,600 --> 00:04:53,069 Iron is used to make irons, 55 00:04:58,840 --> 00:05:01,992 as well as thimbles and knives. 56 00:05:04,920 --> 00:05:07,719 An iron horseshoe is a popular item, 57 00:05:07,880 --> 00:05:10,600 as it brings its owner good luck. 58 00:05:11,960 --> 00:05:15,715 You've probably seen one in your parents' car. 59 00:05:17,640 --> 00:05:21,793 Amongst the most regular users of iron in a professional capacity 60 00:05:21,960 --> 00:05:26,512 are the police force, because iron is used to make handcuffs. 61 00:05:31,080 --> 00:05:33,231 And also this, 62 00:05:33,400 --> 00:05:36,598 the face shackle, worn by petty criminals. 63 00:05:36,760 --> 00:05:39,878 The face shackle is a kind of portable prison, 64 00:05:40,040 --> 00:05:43,954 which must be worn around the clock for periods of up to 18 months, 65 00:05:44,120 --> 00:05:46,999 or three years if you're a repeat offender. 66 00:05:47,960 --> 00:05:51,749 The cheapest kind of iron in modern usage is pig iron, 67 00:05:51,920 --> 00:05:54,640 so called because it's manufactured by pigs. 68 00:05:54,800 --> 00:05:56,280 (CRASH) 69 00:05:56,440 --> 00:05:58,875 Pigs are much more cost-effective than humans, 70 00:05:59,040 --> 00:06:02,431 and they work far longer hours than any man would tolerate. 71 00:06:02,600 --> 00:06:05,479 There are currently plans for them to have their own trade union, 72 00:06:05,640 --> 00:06:09,190 although whether this would work in reality, nobody knows. 73 00:06:15,800 --> 00:06:17,792 An experiment was carried out 74 00:06:17,960 --> 00:06:21,715 to illustrate the effects of electricity upon iron. 75 00:06:22,240 --> 00:06:27,269 First, an iron pyramid is placed upon the work surface. 76 00:06:34,320 --> 00:06:37,791 Next, the pyramid is connected to an electrical circuit, 77 00:06:37,960 --> 00:06:40,998 powered by a 9-volt battery. 78 00:06:53,880 --> 00:06:57,237 We're going to feed both an AC and a DC current 79 00:06:57,440 --> 00:06:59,397 through the ferric pyramid, 80 00:06:59,560 --> 00:07:04,032 and so the battery itself is connected to the mains. 81 00:07:07,120 --> 00:07:10,750 We're working with AC/DC because it's heavy metal. 82 00:07:10,920 --> 00:07:13,674 (WHIRRING) 83 00:07:15,280 --> 00:07:18,478 We're going to turn on the current now, 84 00:07:18,640 --> 00:07:21,553 so get ready to take down notes from the screen. 85 00:07:24,400 --> 00:07:26,392 (BUZZING) 86 00:07:33,640 --> 00:07:36,030 Did you see that? 87 00:07:36,200 --> 00:07:39,989 The bolt of electricity passed right through the building. 88 00:07:40,160 --> 00:07:42,391 Let's take a look outside. 89 00:07:53,520 --> 00:07:56,991 An enormous pair of scissors has appeared in the sky 90 00:07:57,160 --> 00:07:59,152 directly above the laboratory. 91 00:08:00,720 --> 00:08:02,712 And after a few moments... 92 00:08:06,440 --> 00:08:08,432 ..it's gone. 93 00:08:09,640 --> 00:08:12,200 It's an old experiment that you've probably seen before, 94 00:08:12,360 --> 00:08:14,795 but well worth trying nonetheless. 95 00:08:19,000 --> 00:08:23,199 Now hand in your copybook to your teacher or head of class. 96 00:08:26,400 --> 00:08:30,314 In the next programme, we will look at flowers.