00:00:00 Hello, I am Harry Sello. It is my pleasure to introduce Tempest in a Test Tube, a television show which made its debut August 24th, 1955, on KQED Channel 9, the educational station for the San Francisco Bay Area.

00:00:20 Tempest was a series of 53 half-hour shows pioneering a new approach in which I, as lecture demonstrator, gave live, unrehearsed presentations of a series of chemical experiments.

00:00:35 These were designed to illustrate basic, simple chemical principles.

00:00:41 The purpose was to stimulate an interest in chemistry by teenage students and by adults.

00:00:48 The talks and experiments had to be entertaining, educational, and simple.

00:00:54 Spontaneity and liveliness were key to the approach.

00:00:58 All the experiments used in the shows were designed and constructed by members of the California section of the American Chemical Society.

00:01:07 The participants were employed by the Shell Development Company, Emeryville, and by Chevron Research, Richmond.

00:01:15 A grant of $52,000 from the Ford Foundation and National Educational Television permitted the filming of the first 24 shows of the series.

00:01:26 The management for the ACS consisted of Alan Nixon, section chair, Fred Strauss, TV committee chair, myself as first emcee, and Aubrey McClellan, second emcee.

00:01:40 We four constitute the core of the present committee.

00:01:45 The series was extremely popular then with KQED viewers of all ages.

00:01:53 The senior chemist committee of the California section today is determined to revive Tempest for the benefit of elementary schools,

00:02:03 high schools, adult education classes, ACS local sections, historical archives, TV stations, and similar organizations.

00:02:13 We believe in chemistry as a second language.

00:02:19 While basic principles have not changed, practices have.

00:02:24 Forty-five years ago, such simple chemical demonstrations were not treated with the degree of safety considerations that they are today.

00:02:33 Today, even such simple demonstrations would be carried out with the proper regard for safety glasses, shields, protective gloves, laboratory coats, and visible fire extinguishers.

00:02:48 The principle of safety first would be explicitly present as part and parcel of a modern Tempest in a Test Tube.

00:03:03 The principle of safety first would be explicitly present as part and parcel of a modern Tempest in a Test Tube.

00:03:13 .

00:03:42 Tempest in a Test Tube, a series of experiments designed to explain the mysteries of chemistry and the laws that govern it.

00:03:58 Produced by KQED San Francisco, in cooperation with the California section of the American Chemical Society, for the Educational Television and Radio Center.

00:04:22 And now let's go to our laboratory and meet Dr. Harry Sello.

00:04:28 Hello. I'd like to show you the properties of some very interesting materials.

00:04:40 Here is a sample of an unusual metal.

00:04:48 This is a soft metal, can be cut almost like cheese.

00:04:57 Has a silvery luster to it after a fresh surface is exposed.

00:05:02 I'll explain the reason for keeping it in this liquid in just a moment.

00:05:10 Pour a little bit of water in this beaker.

00:05:19 Just block this to get the oil, which is the liquid in the jar, get this removed from the metal.

00:05:34 It cuts very easily.

00:05:41 Now, here is the unusual property.

00:05:57 The metal was skimming around on the surface of the liquid, reacting very violently, and finally exploded, giving forth some fumes.

00:06:05 Let's throw another little piece in there.

00:06:17 Cut a little slice.

00:06:31 Blot it again.

00:06:41 The liquid is skimming around on the surface.

00:06:52 Just throw this here on the floor and stamp on it to put it out.

00:06:57 Fireproof rug anyway.

00:07:00 The sodium, which is that interesting metal, reacted so violently with the water that the hydrogen which was liberated as a result of this reaction caught fire.

00:07:09 I have a little extra piece of the sodium left out here that I'll just put right back in the jar.

00:07:16 And let's look at the second example of these unusual metals.

00:07:21 Here is some similar material, potassium.

00:07:28 It also looks about the same as the sodium did.

00:07:32 Soft, easy to cut.

00:07:34 Cut a little chunk from this.

00:07:44 And blot off the extra oil.

00:07:57 Now, do the same trick.

00:08:04 Caught fire almost immediately. There it is rolling around on the surface of the liquid.

00:08:08 Let a little air back in.

00:08:11 It spatters as it gets used up.

00:08:18 These two materials are samples of elements.

00:08:25 When the two react with water, various elements combine, that is, the elements in water and the sodium and potassium to form compounds.

00:08:38 So here we have an example of some elements.

00:08:41 Sodium, potassium, and the compounds which are formed.

00:08:44 In the one case, sodium hydroxide.

00:08:46 In the other case, potassium hydroxide is formed.

00:08:49 We can tell that something like this has formed if we put a little indicator in, which detects the presence of basic material.

00:09:01 Turns quite dark after being colorless, showing the presence of alkaline material or basic material.

00:09:10 For the potassium, same thing.

00:09:17 We know quite a few elements in nature.

00:09:22 In fact, here is a table containing all of the known elements.

00:09:28 This chart is called, or table, is called a periodic chart, which I'll explain in just a moment.

00:09:33 I said that this shows all of the known elements. That's not quite true.

00:09:37 Several have been discovered in recent years, which, because of the date of this chart, are not shown.

00:09:43 There are three more than are shown here.

00:09:46 There's 98 shown on this chart, or there are 98 shown here.

00:09:50 We have three more to add.

00:09:52 99, 100, and 101.

00:09:55 They are named, respectively, einsteinium, fermium, and mendelevium, after three famous scientists.

00:10:06 These elements, shown here, are arranged in order of their weights.

00:10:12 The lightest one on top, hydrogen, all the way down through, increasing in weight,

00:10:20 down to the heaviest end of the periodic table, that is, heavy element end.

00:10:26 There is yet another type of arrangement which makes this the periodic table.

00:10:31 It is not sufficient just to arrange these in order of their weights.

00:10:35 If we add the additional rule that we will arrange the elements in order of their weights, increasing weights,

00:10:42 at the same time putting all those together which have similar properties, like the sodium and potassium,

00:10:48 here is what we find to be the rather interesting case.

00:10:52 We then can lay these out, but we soon find that after we lay out one row of them, these two here,

00:10:58 six, rather, after we lay out this row, we have to come back and put sodium down underneath lithium,

00:11:05 because sodium and lithium have the same property.

00:11:08 The same goes for the next row.

00:11:10 We put potassium down under sodium in the same group, vertical position, group,

00:11:17 because they have the same properties.

00:11:19 Now, because we do this, repeat the rows, excuse me, repeat these horizontal periods,

00:11:27 which these are called, because we repeat these, we call this a periodic table.

00:11:33 Periodic means to vary over and over.

00:11:36 For example, the rising and setting of the sun is periodic.

00:11:41 The rise and fall of tides is periodic.

00:11:44 So we have here, then, a periodic table of the elements.

00:11:49 The elements, then, fall into various general classifications.

00:11:53 On this side, we have metals, sodium, potassium, magnesium, calcium, and so on.

00:12:01 Over in this side, we have nonmetals, oxygen, sulfur, nitrogen, phosphorus, some of the more common ones.

00:12:13 Down along a diagonal, running about like so, underneath this staircase arrangement,

00:12:21 we have materials which sometimes exhibit the properties of metals

00:12:25 and sometimes exhibit the properties of nonmetals.

00:12:31 This is a rather ingenious arrangement of the elements, this periodic chart,

00:12:36 because we can tell what the property of any given element will be

00:12:41 knowing the property of the one above it.

00:12:43 We will see later that we can say something about sulfur because we know the property of oxygen.

00:12:48 We already have seen that if we know sodium reacts violently with water,

00:12:51 we would expect the potassium to do the same.

00:12:54 The gentleman who first laid these out in the most systematic way

00:12:58 was a Russian by the name of Mendeleev.

00:13:01 However, he was examining, back in 1870 or so, many less elements than we have here.

00:13:08 We now know 101.

00:13:09 In Mendeleev's time, there were something like, oh, 63 or 64 known.

00:13:14 By the use of this transparent paper overlay,

00:13:19 maybe we can see just how the table looked when Mendeleev knew it.

00:13:24 Of course, he had a more clear one. He didn't have to use transparent paper.

00:13:29 But here is, looking through the paper, is the table or the number of elements as Mendeleev knew them.

00:13:38 You see, where the black portions are, the darker portions,

00:13:43 were then, were elements which were then unknown.

00:13:46 Here is a whole row of them unknown, a whole group.

00:13:50 Here are some individual ones unknown.

00:13:54 Here are two, almost two complete families of elements which were unknown at that time.

00:13:59 The rare earths, they're called.

00:14:03 So there were quite a few unknown.

00:14:06 Now Mendeleev realized this, and he predicted on the basis of the missing holes in the table,

00:14:12 he predicted that elements would be found one day which would have certain properties.

00:14:16 For example, here is silicon.

00:14:19 Underneath silicon was a blank space.

00:14:22 We knew at that time had just been discovered gallium, also was known arsenic.

00:14:27 Arsenic was also known.

00:14:30 But this one had not been discovered.

00:14:32 That said, this will one day be discovered, of course, and it will have properties similar to silicon.

00:14:38 I will call it eka-silicon, meaning another kind of silicon.

00:14:43 He did the same, actually, just prior to this time.

00:14:46 He did the same for gallium, and in 1871 or so, 1875 actually, I correct myself there, gallium was discovered.

00:14:54 He had called it eka-aluminum.

00:14:56 You see, here is aluminum right above it, gallium right here.

00:14:59 He predicted the properties of something he called eka-aluminum.

00:15:03 In 1875, as I say, gallium was discovered, and it did have these properties.

00:15:08 In fact, on the card I have up here on the table, we can show the accuracy of Mendeleev's predictions.

00:15:18 In 1871, Mendeleev predicted that eka-silicon would have an atomic weight of 72, because you see he knows the neighbors on either side.

00:15:34 He knows the one above it.

00:15:36 It would have a density of 5.5, and the density of its oxide would be about 4.7.

00:15:44 He was reasoning from the properties of the other elements.

00:15:48 In 1886, in Mendeleev's lifetime, some 15 years later, an element was discovered in Germany by a man by the name of Winkler.

00:16:00 He called it germanium, after the country in which it was discovered.

00:16:05 And here are the properties of the germanium as compared to the eka-silicon which Mendeleev predicted.

00:16:11 72.6 against 72, 5.47 against 5.5, 4.70 against 4.7, right on the button for the latter one.

00:16:19 In fact, quite accurate for all three.

00:16:22 This demonstrated how useful a periodic arrangement of the elements could be, because you know in a sense what to look for.

00:16:31 The answer is to find it.

00:16:35 Many elements have been discovered since Mendeleev's time.

00:16:38 By the way, the peculiar spelling of Mendeleev here is just one of the many accepted kinds of spelling.

00:16:45 You see, it's a Russian name, and it's transliterated, that is, it's changed over into sounds.

00:16:51 The pronunciation is Mendeleev.

00:16:53 Well, one way of coming out of Mendeleev is to include a J, as the Germans did when they first translated Mendeleev's articles.

00:17:01 Sometimes you'll see the J omitted.

00:17:03 Sometimes it'll be spelled I-E-V.

00:17:05 It's all the same man, Mendeleev.

00:17:09 Here are some samples of elements chosen from the periodic table.

00:17:16 Magnesium, a metal, little turnings.

00:17:20 Here's a magnesium ribbon.

00:17:22 Mercury, another metal, but a liquid, as it occurs naturally.

00:17:27 Here is carbon.

00:17:29 Three forms of carbon.

00:17:31 Ordinary charcoal, or amorphous carbon, having no particular structure.

00:17:36 In the pencil is another form of carbon, graphite.

00:17:39 A pencil does not have lead.

00:17:40 That is, a lead pencil doesn't have lead, it has graphite, which is a form of carbon.

00:17:44 Here is a rather rare variety of carbon, in the range in the form of a little ring, which can be seen on people's hands once in a while.

00:17:53 This is a rather precious form of carbon.

00:17:55 It's pure carbon, crystal clear.

00:17:58 It looks like glass, but it isn't glass.

00:18:01 It's a diamond.

00:18:02 By the way, if you ever wanted to test something like this to tell whether it's pure carbon, all you'd have to do would be to burn it.

00:18:07 If it left no ashes, then it was pure carbon.

00:18:11 A test which is not duplicatable.

00:18:13 Here is sulfur.

00:18:15 And finally, in the last little tray here, is some iodine.

00:18:22 These are all elements, just samples of elements from the periodic table, which were known, as a matter of fact, at the time of Mendeleev.

00:18:30 I'll just cover the iodine because it evaporates, or rather, sublimes rather readily, and the fumes are not too comfortable.

00:18:41 We have now looked at examples of elements and seen how they react to form compounds.

00:18:48 An element, then, is a material, all of whose atoms are of the same kind.

00:18:55 A compound, the chemist defines, as being a material which is a combination of two or more elements.

00:19:04 Also, in a compound, we would say all of the molecules are of the same kind.

00:19:09 We will talk more about atoms and molecules in a succeeding talk.

00:19:15 We've also seen, then, that Mendeleev's predictions about the periodic table were striking and did come true.

00:19:22 One of the most striking, other than the one we just looked at, was the fact that before Mendeleev died, a whole group of elements were discovered, the rare gases.

00:19:35 They were not known at Mendeleev's time, that is, when he first put out the periodic table.

00:19:41 They were then found and seemed to fit perfectly as arranged in the periodic table all along this group.

00:19:48 Another striking verification.

00:19:51 Let's look at further properties, then, of some more elements.

00:20:01 I've set this water to boiling.

00:20:04 And now the taper is on fire.

00:20:09 If I just put that in the steam, it goes out.

00:20:12 The taper is essentially burning carbon, and it will go out because there's not enough air for the carbon to continue burning.

00:20:20 So let's look at what happens when we do the same thing with magnesium, a metal which has the property of burning also.

00:20:30 I'll just light the magnesium in the tip of the burner flame, hold it in the steam, and where the carbon flame went out, the magnesium burned very easily.

00:20:42 This shows that magnesium can combine very rapidly with water and continue burning if the water is present in the form of steam.

00:20:52 This was one reason why magnesium was used in incendiary bombs so effectively.

00:20:57 You see, you can't put it out. You throw water on it, and it doesn't put it out, or you use CO2, and that won't put it out.

00:21:03 Magnesium can react with either the CO2 or even with nitrogen in the air to form compounds.

00:21:08 It is a very reactive element.

00:21:10 We've now looked at the properties of metals.

00:21:12 What about nonmetals?

00:21:14 According to Mendeleev, oxygen and sulfur are in the same group because they should exhibit the same properties.

00:21:27 Well, do they? Let's take a look.

00:21:33 Here's a cylinder full of oxygen.

00:21:35 I'll just fill up this test tube with some oxygen, holding the tubing in the test tube.

00:21:55 Now, if the oxygen will stay there long enough, I'll just light this little bit of steel wool, which glows in air, but which in oxygen glows much more brightly.

00:22:18 Evidence of the fact that iron reacts very readily with oxygen.

00:22:24 So, we then go on further with this point, and as we've said, if oxygen and sulfur have the same property, they should then react with iron, both in the same way.

00:22:35 Here's a test tube containing steel wool at the center portion of it, and at the bottom, underneath the steel wool, or down below it here,

00:22:46 is a little batch of sulfur powder.

00:22:49 The same type of powder we just saw exhibited in that little array of elements.

00:22:56 Let's heat the sulfur and see what happens.

00:23:02 First, adjust the burner to a hot flame.

00:23:05 It just occurs to me that for this one, I should be wearing my safety glasses, in case the test tube decides to break and a piece of glass decides to fly.

00:23:14 This will be the safe way.

00:23:20 The sulfur now, where the burner flame is hitting the test tube, is beginning to turn black, melting into a liquid and beginning to turn black.

00:23:27 Also, some vapors are being formed, sulfur vapors.

00:23:36 Now, the vapors are coming up around the iron, and the iron there is beginning to glow.

00:23:42 It continues to glow as the sulfur vapors run over it.

00:23:45 This shows, then, that sulfur reacts with iron much in the same way, almost as rapidly, or as far as we can see in this experiment, just as rapidly, as sulfur reacts with iron.

00:23:59 This shows, then, that sulfur reacts with iron much in the same way, almost as rapidly, or as far as we can see in this experiment, just as rapidly, as oxygen reacts with iron.

00:24:18 On the one hand, iron oxide is formed. This is the compound formed between the elements iron and oxygen.

00:24:24 In the second case, iron sulfide is formed, the compound between iron and sulfur.

00:24:30 This shows, then, that the arrangement of oxygen and sulfur in the periodic table is a true one.

00:24:35 They have a similar property as illustrated here.

00:24:38 Well, we've also said that if sulfur, for example, is over on the right-hand side of the table with oxygen, it ought to exhibit the property of a non-metal.

00:24:51 We said that this side were non-metals.

00:24:54 Let's take a look and see if that's the case.

00:24:58 For this, I'll leave my burner over here.

00:25:07 Adjust this to a hot flame again.

00:25:10 Now, let's put a little bit of water in this jar, and in the water, I'll place some indicator solution which will detect the presence of acid or base, depending on whatever is there.

00:25:39 Right now, it indicates that neither is there. It's neutral, being a dark color.

00:25:44 Let's fill out a little sulfur here.

00:25:53 All right, you shovel it out on the spoon.

00:25:59 You want just the right amount because you don't want too much sulfur burning around.

00:26:07 It creates fumes which are uncomfortable.

00:26:10 And put the sulfur in the flame of the burner, set it to first melting, and then finally it's burning.

00:26:21 The flame is very difficult to see because it's quite a pale one.

00:26:24 There it is burning now.

00:26:25 It's beginning to generate a kind of a smoke.

00:26:29 Those fumes are sulfur dioxide, the combination of sulfur and oxygen.

00:26:34 So here's an interesting case.

00:26:35 Though the elements are both in the same group, sulfur can react with oxygen and does.

00:26:41 It burns in the presence of oxygen as shown by this experiment.

00:26:44 The compound formed is sulfur dioxide, a very pungent, smelly kind of a gas.

00:26:51 I think that's about enough sulfur dioxide in there.

00:26:54 It's actually still burning.

00:26:55 I'll just lay it down over here on the pad.

00:26:59 Now, cap the jar and watch carefully as I shake this to dissolve the gas in the liquid.

00:27:08 Changed color almost immediately.

00:27:11 The indicator changed color showing that where it was neutral before, it is now almost colorless.

00:27:18 Actually a slight yellow tinge, showing the presence of an acid.

00:27:23 Sulfur dioxide dissolves in water and forms sulfurous acid.

00:27:28 Now, we have illustrated that metals reacting with water lead to,

00:27:34 or active metals reacting with water lead to bases.

00:27:37 Sodium and potassium each lead one to sodium hydroxide, the other to potassium hydroxide.

00:27:41 These were bases.

00:27:42 Showed a change there for an alkaline material.

00:27:45 Here is a case where the nonmetal oxide, the sulfur dioxide, reacts to form an acid.

00:27:52 Now, how about those in between?

00:27:55 Are there any such?

00:27:56 Yes, there are.

00:27:58 If we choose from this diagonal group that I mentioned before,

00:28:01 as being those elements which have the properties both of a metal and a nonmetal,

00:28:06 we should be able to illustrate that.

00:28:08 For example, here is aluminum.

00:28:10 You see right under this sort of step arrangement.

00:28:13 Here is aluminum.

00:28:15 It should, if the periodic table is correct,

00:28:18 exhibit the properties of both a metal and a nonmetal.

00:28:21 Let's take a look.

00:28:27 Powdered aluminum.

00:28:28 Let's see now.

00:28:29 Here we have some sodium hydroxide, which is a strong base.

00:28:33 We actually made a little sodium hydroxide in the first experiment.

00:28:41 And here is some hydrochloric acid, HCl.

00:28:51 To make the experiment more visible, let's add a pinch of tide, a detergent, to both.

00:28:58 Any detergent would work.

00:28:59 This just happened to be handy.

00:29:03 Shake it up a bit.

00:29:05 Now, in the sodium hydroxide, we'll throw a little aluminum.

00:29:16 There is a reaction almost immediately as the layer of suds are rising.

00:29:20 I'll do the same in the HCl.

00:29:25 This reaction also has started, but it's a little slower than the other.

00:29:29 What is the gas which is escaping?

00:29:31 Let's see if we can tell.

00:29:34 Hydrogen.

00:29:39 The acid reaction is a little slower, but it is beginning to form some suds.

00:29:44 We'll come back to it in just a second as we summarize what we've seen.

00:29:48 Well, what have we learned about elements and compounds?

00:29:52 First, an element is a material all of whose atoms are of the same kind.

00:29:58 A compound is a material made by a combination of two or more elements.

00:30:04 A compound is a material all of whose molecules are of the same kind.

00:30:08 We showed some samples of elements, including three interesting forms of carbon.

00:30:13 Well, one interesting form of carbon, a diamond.

00:30:16 We saw that there are 101 known elements, a periodic table as invented by Mendeleev.

00:30:23 Here comes the hydrogen in a delayed reaction.

00:30:26 Let's just test it while it's here.

00:30:28 If I could so much, it doesn't want to even ignite.

00:30:32 Let's let it settle here.

00:30:34 Excuse me.

00:30:36 There's a reaction anyway.

00:30:38 I was saying that Mendeleev invented the periodic table,

00:30:41 and it's an arrangement of all the elements arranged according to their similar properties and their weights.

00:30:46 We then saw that we finally had an element in which it exhibited both the properties of metals and nonmetals.

00:30:52 This was called an amphoteric element, meaning it has both properties.

00:30:57 This was, in this case, aluminum.

00:30:59 Aluminum reacted both with sodium hydroxide and with an acid.

00:31:05 Now, maybe there's still a little bit of hydrogen left over.

00:31:10 Let's see if we can still shake loose a little hydrogen.

00:31:15 Well, it puffed a little, but there isn't much.

00:31:19 Maybe another shot of acid would do it.

00:31:21 Or here, I'll find a little aluminum just for kicks.

00:31:29 Here it comes.

00:31:30 Now, well, it puts out the flame certainly.

00:31:33 The hydrogen is coming off too fast.

00:31:35 Difficult to actually set it on fire.

00:31:40 There it is, anyway.

00:31:42 Thank you.

00:32:09 This is National Educational Television.