Hey everybody, welcome back to X-Men. I'm 5, the podcast where we take the questions you've always wanted to ask and talk about them in a way that's easy to understand. We're your hosts, I'm Tim. And I'm Kevin.
So Kevin, there's so much discussion everywhere about the amount of oxygen and carbon in our atmosphere, but 80% of the air is nitrogen. So where does nitrogen fit into the whole circulation process? How is it made and how is it used? Yeah, it's funny how it's 80% of our atmosphere, but it's rarely talked about, right?
Exactly. So nitrogen is very important. And one crucial aspect of nitrogen is that it's very inert, which means it's not reactive and it's not easy to take out of the air for use of reactions. So if you compare it to other elements in the air, nitrogen kind of looks sad and lonely because it's usually all alone, like literally.
Carbon can be shaped into gases, solids like diamonds, and soft solids like graphite. Oxygen as well can bond with many things, like hydrogen, becoming hydrogen monoxide, which is liquid gas, or, of course, water, carbon, and many other elements. But it's this inert nature that's what makes it less interesting to talk about usually. I see.
Poor nitrogen. But Tim, explain that word inert. What does that mean exactly? Sure.
So the nitrogen molecules, they're very stable, and therefore it's hard to do anything with or to them. While nitrogen N2 is very inert, it may react with oxygen at high temperatures forming nitrogen oxides, like NO, NO, NO2. And this can happen within combustion engines of various types, too. The problem is that these compounds are usually very toxic, so a great amount of care is taken to manage a combustion in order not to let them form and or filter them as they exit.
An example of this are the catalytic mufflers that are put on cars. I see. What about nitrogen in nature? So in nature, there's a nitrogen cycle, actually.
Essentially, some amount of nitrogen is essential for plants and animals to create proteins. So let me explain like I'm five, by starting with the nitrogen gas in the atmosphere, and kind of go through the cycle here. You can do that as a four-step process. Step one, nitrogen gas is breathed in by animals, and most of it is actually breathed back out, but much of it remains in the bloodstream of the animal.
Step two, ammonium and ammonia are produced by the animal's waste products. In humans, this is actually released through urine. Step three, ammonium is broken down into something called nitrites and nitrates by bacteria. And then finally, step four, nitrites and nitrates are used as fertilizers for plants and algae, and some bacteria will eat them, too.
These will, in turn, some of it back into nitrogen gas, starting the cycle all over again. And it's that use case of fertilizer that means that we as a human species really do care quite a lot about the nitrogen cycle, don't we? Yes, we do. So much so that we use a synthetic process to make ammonia called the Haber process, because we need lots of ammonia to grow crops on this huge industrial scale the way we do.
In fact, we spend over 1% of all the world's energy doing this, essentially to accelerate the nitrogen cycle. Now, there's also a reason why divers know a lot about nitrogen, I believe. That's because nitrogen gets really wonky as you breathe it at high pressures. Such as when you're underwater.
As you go down, your body becomes more saturated. Now, this isn't too big of a deal until you try to resurface without giving your body enough time to kind of wash out the nitrogen from your tissues. What can happen here is something called DCI, or decompression illness. What happens to you in DCI?
Well, breathing nitrogen at death has effects ranging from making you tipsy, drunk, and hallucinating, or even death, depending on the death. It's something that scuba divers are taught about, because even at about 70 feet, you can start to feel mild effects on this. So one interesting side effect of nitrogen being the primary gas we breathe is that if you breathe pure nitrogen, you know, basically with no oxygen, your lungs don't start burning. But over a couple of minutes, you just get giddy, and you slip into unconsciousness, and eventually die.
Actually, that happens with any inert gas except CO2. The burning can't breathe feeling is not triggered from a lack of O2, but from an excess of CO2. It's why confined spaces can be so dangerous. Interesting.
Now, some people talk about how lightning puts nitrogen into the Earth. Oh, that's because, if you think about it, the atmosphere is already about 80% nitrogen and 20% oxygen. So what happens when lightning happens is the lightning tears the N2 and O2 molecules apart, and they recombine back to the original gases or to nitrogen oxides. These nitrogen oxides combine with water vapor to form nitric acid, which then rains down and reacts with soil particles to form nitrates which then plants can use.
Okay, so if that's the high-temperature use case and effect on nitrogen, we should also end with the opposite end of the spectrum as well. Liquid nitrogen has lots of use cases. Why is this? Yes, and lots of fun use cases as well, such as ice cream.
This is because at the atmospheric pressure, nitrogen boils at something really cold, something like negative 196 degrees Celsius. That's negative 321 degrees Fahrenheit. So nitrogen was first made into a liquid in 1883. But it was really during World War II that the production of liquid nitrogen became common, and this lowered the cost of producing.
Now, after the war, cool new use cases were found for liquid gases, like water removal, storage, and preservation of cells, even to cool electronics, such as infrared sensors, and of course, infrared fluid preparation for food such as ice cream. But, but, you have to really be careful with this. In 2012, a young woman's stomach had to be removed after drinking a shot with liquid nitrogen still in it. Ooh, you want to be careful of that.
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