# What Would Happen If the Atmosphere Was Made of 100% Oxygen? ## Метаданные - **Канал:** Thoisoi2 - Chemical Experiments! - **YouTube:** https://www.youtube.com/watch?v=T9d8BR0u7Vc - **Дата:** 20.12.2025 - **Длительность:** 19:49 - **Просмотры:** 38,186 - **Источник:** https://ekstraktznaniy.ru/video/20440 ## Описание Patreon: https://www.patreon.com/Thoisoi Attention! This video shows dangerous experiments! Do not repeat the experiments shown in this video! Hello everyone! In this video, I explore how ordinary materials burn under normal atmospheric oxygen and what would happen if the concentration reached 100%. I demonstrate experiments with wood, nuts, cigarettes, sulfur, selenium, and various metals inside quartz tubes with a constant air supply. I also explain how oxygen first appeared on Earth, how its concentration changed over billions of years, and how it shaped life and evolution. Along the way, I show how reactive different elements become when oxygen is plentiful and why some metals ignite much more easily than others. Welcome to my channel! It's dedicated to experiments in inorganic and organic chemistry! Here, you can find a lot of chemical experiments, each of which contains explanations that will be understandable even to people who are not into chemistry. In my video experiments, ## Транскрипт ### Segment 1 (00:00 - 05:00) [] Hello everyone. Right now I'm holding a burning flame in my hand. Ordinary matches with a maximum burning temperature of about 1,400° C. And all of this is happening with an oxygen concentration in the atmosphere of just 21%. The rest is made up mostly of inert nitrogen and carbon dioxide. I wonder what would happen to this match if the oxygen concentration were 100%. And what would actually happen on our planet if it's atmosphere were made up of pure oxygen? Well, let's find out. I think many of you don't know that the presence of gaseous oxygen in the atmosphere of any planet is actually very rare. For example, in our solar system, apart from our own planet, we still haven't been able to find any acceptable concentrations of oxygen in the atmospheres of other planets or their moons. As for exoplanets, I won't even mention them since detecting oxygen there is even more difficult. However, if it does become possible, it could indicate a high probability of life existing on that distant celestial body. The thing is if you look at the table of electro negativity of all elements you'll notice that oxygen is almost the highest which makes this element a very strong oxidizer. The only element stronger than it is florine but when it comes into contact with the atmosphere it very quickly turns into hydrofluoric acid. So in its free form it only lasts a couple of seconds. But unlike florine oxygen isn't such a reckless oxidizer and it can remain in the atmosphere for quite a long time. Nevertheless, it reacts quite easily with many substances, for example, with any organic matter. All it takes is a single spark, and any dry organic material like grass will ignite and burn until the fuel runs out since the supply of oxygen in our atmosphere is practically endless. But here's an interesting question. Where did the oxygen on our planet come from in the first place? It turns out that after the Earth formed, just like on other young planets, its atmosphere consisted mainly of nitrogen, carbon dioxide, and water. There was practically no oxygen. At the same time, due to high volcanic activity, the entire Earth back then resembled present-day Iceland. There were hot springs and volcanoes everywhere, saturating everything around with volcanic gases. That is why the first forms of life used carbon dioxide, iron ions, and sulfur as energy sources. Just as it happens now, for example, on the ocean floor near the so-called black smokers, that is underwater geothermal vents. But still, about 3. 5 billion years ago, as the earth cooled and the number of geothermal zones with free heat decreased, a new type of organism appeared on our planet. Cyanobacteria, which could already use the energy of the sun. They synthesized carbohydrates from carbon dioxide and water, and oxygen turned out to be a byproduct. At first it was absorbed by the oceans since they contained a lot of divolent iron which is very easily oxidized by oxygen to trialent iron. But later this buffer was depleted and oxygen broke through into the atmosphere causing a full-blown oxygen catastrophe. This happened about 2. 5 billion years ago as it killed off many anorobic bacteria that cannot live in the presence of oxygen like those that live in our intestines. At the same time, the oxygen that formed in the atmosphere created the ozone layer. Thank you. It protects Earth's inhabitants from harsh ultraviolet radiation which allowed many types of living organisms to move onto land without damaging their DNA from harmful rays from the sun. Over time, the concentration of oxygen continued to rise, reaching a record 35% about 320 million years ago during the Carboniferous period. Yes, it was truly a strange time with insects the size of cats, endless impenetrable tropical forests, and incredible wildfires in arid regions. But over time, with the emergence of a new type of fungus capable of decomposing wood, as well as changes in the climate, there were fewer plants on Earth, and the oxygen level gradually began to fall until it reached the current 21%. So far, our planet is unique in this regard because with the help of oxygen, biochemical processes in living organisms occur much more efficiently than without it. Just look at a simple example. Anorobic oxidation of glucose or glycolysis, which produces only two molecules of ATP, that is the compound that serves as the energy source in our bodies. Therefore, without oxygen, living organisms developed rather slowly. But with the appearance of oxygen and the emergence of a new biochemical pathway called the Krebs cycle, which releases six times more energy from glucose, the development of organisms and evolutionary processes, accelerated several times over. Still, besides sustaining life, oxygen is also ### Segment 2 (05:00 - 10:00) [5:00] a powerful oxidizer and supports combustion very well. Let's first see how familiar things burn at a constant oxygen concentration of 21%. For this, I decided to conduct the experiment in quartz tubes since this material is highly heatresistant and besides quartz can withstand sudden temperature changes very well without forming cracks. Since the tubes were originally about a meter long, I decided to first cut them into small sections using a diamond glass cutter. This process isn't the easiest, but if you get the hang of it, the cut turns out pretty even. After I cut the tubes to the desired length, I secured one of them in a stand and connected a regular aquarium pump to it. This way, air will flow through the tube and the oxygen concentration at the ignition point will always be 21%. First, I decided to light a regular toothpick and see how it would burn at the normal oxygen concentration in the air. Yes, with this kind of air flow, combustion happens quite quickly and after just a few seconds, only ash was left of the toothpick. Interestingly, with this constant supply of air, you can burn almost any organic material. For example, a regular pistachio. At first, when heated with a torch, the fat from the pistachio nut started to burn. Then, the pyrolysis of proteins and everything else began, which produced a lot of pyrolysis gas. Since the oxygen concentration here is at atmospheric level, not all the gases had time to burn in the tube. So, I simply finished burning some of them off with a gas torch. And as a result, after a few minutes, the pistachio turned into a piece of charcoal, which apparently didn't want to burn any further because it was being cooled by the incoming stream of air. And of course, how could I not try lighting a regular cigarette, which even with a good supply of air, burned rather sluggishly and eventually turned into some kind of nicotine charcoal? Even a powerful exhaust fan couldn't save me from the smell. Yes, burning organic matter with a good supply of air is certainly interesting. However, it will be even more interesting to observe the combustion of other chemical elements, for example, some non-metals. I think we can start with sulfur. After being heated with a burner, it first simply melts and then ignites with a dim blue flame, producing sulfurous gas or sulfur dioxide. Yes, sulfur actually burns quite well as it is. But will its homalogue selenium ignite with such a good supply of air? At first, just like sulfur, it starts to melt and then with further heating, it begins to evaporate, producing red selenium vapors. Unfortunately, I didn't observe any combustion here. Although, if you try to ignite the selenium vapors produced with a torch, they seem to start burning with a bluish color. But inside the tube itself, I didn't see any burning. Apparently, gray selenium, which is the form it's usually sold in, is a rather stable form of this element. And it doesn't ignite just like that. Well, let's move on to the combustion of more active substances, namely some metals. First, I decided to ignite the most commonly burned metal, namely magnesium. I think everyone knows that in air, it burns with a bright white light with a very powerful light output. I wonder what will happen if the air supply to the hot magnesium is at its maximum. After a good preheating, the magnesium ignited, but the flame wasn't as bright as I expected. Overall, the combustion turned out to be quite calm. Most likely, the high reactivity of magnesium played a role here, causing it during combustion to also react with the quartz glass, forming a thin film of amorphous silicon and a mixture of psilocides at the bottom, magnesium. In fact, there are other metals that burn in air even better than magnesium, namely titanium and its homalues. That is why titanium, not magnesium, is used in pyrochnic fountains to create white sparks. Well, let's see how titanium powder burns when air is blown through it. At first, when heated, it only dulled slightly, but then it quickly caught fire with a very bright yellow flame, which looked quite beautiful. In the end, only titanium dioxide powder remained. For comparison, I also decided to try igniting so-called titanium sponge, the primary product in titanium production. This material is quite porous and in theory, it can also catch fire. But still, even after prolonged calcination in the presence of ordinary air, this metal in such a form didn't really catch fire, but only became covered with a multicolored film of titanium dioxide. If you look at the periodic table below, titanium is its homalogue, zirconium. Let's see how its powder will burn with an active supply of air. Interestingly, even with only slight heating, zirconium powder ignited even faster than titanium, burning up with a bright yellow flame and the formation of zirconium dioxide. This reaction turned out to be quite lengthy, so new portions of the forming zirconium dioxide kept ### Segment 3 (10:00 - 15:00) [10:00] emerging from the reaction site. It's also interesting that today this metal is used as a cladding for nuclear fuel pellets. These pellets are assembled into the very fuel rods at the heart of a nuclear reactor. In emergency situations, for example, when nuclear fuel overheats and partially melts, overheated zuconium can react with water, releasing a very large amount of hydrogen, as happened during the Fukushima nuclear power plant accident. But in this reaction, it is clearly visible how the addition of water can intensify the burning of metals like zuconium. After zuconium, I decided to ignite its heavier counterpart as well, that is powdered metallic halfnium. The combustion turned out to be almost the same as with titanium, although it was 10 times more expensive since hapneium is not a cheap metal. A cheaper option is zinc, which can also burn in air, for example, during the smelting of brass, where its content can reach up to 20%. For another experiment, I put zinc powder into a tube and connected an air supply. Under these conditions, the zinc burned quite calmly, forming zinc oxide, which also has the property of thermocchromism. that is when heated it is yellow and after cooling it turns white. But if you compare zinc with iron powder, there is still a difference. Iron hardly ignites at all. It just smolders slightly at the usual oxygen concentration in the air. By the way, from my previous experiments, when we tried to melt some refractory metals, I remember that tungsten and tantelum, they oxidized quite strongly at high temperatures, which is also why I decided to try igniting these metals. First, I placed the powder of the most refractory metal, tungsten, into a quartz tube and connected an air supply. After some time, this metal began to burn rather slowly, forming tungsten triioxide as a result. But it turned out that this was just the beginning, and the reaction kept going, continuously producing new portions of yellow oxide. At this point, I almost wanted to say, "Pot, stop cooking. " Because in the end, the volume of the tungsten oxide obtained was about four times greater than the original dense metal powder. I think it's all because tungsten triioxide is about three times less dense than the metal itself. Metallic tungsten, which is why this unusual effect occurs. After tungsten, I decided to take some tantelum powder, which is also a very heavy and refractory metal. After heating, it ignited quite easily and turned out to be quite bright when burning. Let's compare it with magnesium, only the color was slightly yellowish. As with tungsten, the reaction took quite a long time with a significant increase in the volume of the resulting tantalum oxide, which looked rather unusual. Now you've seen the combustion of some metals and familiar substances at the normal oxygen concentration in air. Now let's see what happens if we increase it from 21% to 100%. To do this, I connected an oxygen cylinder to a quartz tube and first decided to see how an ordinary toothpick would burn in pure oxygen. The first few seconds of heating went as before, but then the toothpick was simply annihilated in a matter of seconds with a pistachio in an atmosphere of pure oxygen. The combustion also intensified many times over and was exceptionally bright. This was all because of the sodium atoms due to the table salt that the nut was sprinkled with. Interestingly, under such conditions, combustion is complete and in the end only some salts that are part of the pistachio remained while all the organic matter was completely burned away. While an ordinary cigarette in pure oxygen disappeared in a matter of seconds and didn't even leave behind an unpleasant smell since under such conditions, absolutely all organic substances burn up, including nicotine resins. And by the way, you can even burn a diamond in a similar way since it essentially consists of ordinary carbon, which is easily oxidized by pure oxygen, leaving almost nothing behind after it burns. I also liked how sulfur burns in pure oxygen because under those conditions, it burns with a beautiful blue flame, very bright, and in the end, it leaves almost nothing behind. Silicone, unfortunately, wouldn't ignite even in an atmosphere of pure oxygen. Apparently, this element is not flammable at all. Well, now let's see how some metals burn in an atmosphere of pure oxygen. By the way, according to the literature, the combustion temperature of metals in pure oxygen is considered the highest. It can reach up to 4,500° C. I wonder which metal will burn the hottest. Let's start, just like last time, with a strip of magnesium. Yes, in an oxygen atmosphere, the magnesium practically boiled and burned up in just a few seconds. The temperature here could theoretically reach 3,300° C, which is 200° higher, hotter than the flame of an acetylene torch, which is capable of melting even the most refractory metals. Speaking of which, let's see how those very metals ### Segment 4 (15:00 - 19:00) [15:00] with extremely high melting points will burn. Let's start, I think, with tungsten powder. Yes, in pure oxygen, it burns much faster and brighter, making it glow like a powerful spotlight. At such a high temperature, even the formed tungsten triioxide managed to melt, and some of it even evaporated a bit. So, the burning temperature here definitely exceeded 2,000° C. It's also interesting that fused tungsten oxide, like zinc oxide, has thermocchromic properties. That is, when heated, it turns red and after cooling, it becomes yellow again. After tungsten, I decided to ignite tantalum as well. Its powder ignited with an even brighter flame and surprisingly burned for quite a long time, about three times longer than tungsten. The temperature stayed above 3,000° the whole time, which caused even tantelum penttoxide to start melting and splattering onto the walls of the tube. From such a sudden increase in temperature, even the quartz tube started to give way and eventually cracked, something I had never seen before. Well, let's see how the most flammable metals such as titanium and its homalologues will ignite. Naturally, we'll start with titanium powder. Yes, in pure oxygen. This metal boiled like magnesium, almost completely splattering the inner walls of the tube with droplets of molten titanium, which looked quite unusual. The combustion temperature here could reach up to 3,500°. In addition to titanium powder, as before, I also decided to ignite titanium sponge, but this time in pure oxygen. At first, nothing special happened, but as soon as the titanium heated up to the required temperature, this happened. I had no idea that some metals could simply explode in pure oxygen, splattering burning metal all over the fume hood. Now let's compare the combustion of titanium with zirconium powder since according to reference data this metal may hold the record for the highest burning temperature in pure oxygen. When ignited, this metal like titanium started to splatter the walls of the test tube with droplets of zirconium and it may have even boiled during combustion. If we look at the boiling point of zirconium, which is 4,400° C, we can assume that the combustion temperature of zuconium in oxygen even slightly exceeds this value. And as it turns out, that's exactly the case. So the temperature in this test tube is probably the highest possible that can be achieved by simply burning a substance in oxygen. If you ignite a bit more zirconium in the test tube, such a bright flame can light up almost the entire room. Yeah, now that's power. And finally, I decided to burn something more expensive in oxygen, a relative of zirconium, namely hapneium powder. Basically, the combustion was a bit weaker than that of zirconium, more similar to titanium. And finally, I became curious about how zinc and iron would burn in such a high concentration of oxygen. Zinc does burnt up in just a second under these conditions. While the iron powder actually melted during combustion, turning into something like lava. After the experiments in the quartz tube, I also became curious about how everyday objects would burn in that same concentration of oxygen at 35% which is about what our planet had around 320 million years ago. To test this, I simply directed a stream of oxygen from a cylinder onto a burning rag soaked in oil. When mixed with air at a distance, I think the oxygen concentration here was about 35 to 40%. Interestingly, at this concentration of oxygen, the flame becomes wider rather than yellow, apparently due to more complete combustion of carbon. Well, if the concentration of oxygen in Earth's atmosphere reached even 90%, then most likely life simply wouldn't exist here because at such high concentrations, animals would suffer from oxygen poisoning, and many plants and other materials would become flammable even when wet, as would some metals. So, I think it's a good thing that here on Earth, everything is balanced. Oxygen and the other gases alike. And if you enjoyed this video, as always, don't forget to give it a like and subscribe to the channel to discover even more new and interesting things.