Why is mercury liquid at room temperature?

Daniel and Kelly take a detour into the fascinating world of chemistry to explore why mercury is liquid at room temp. The answer is relatively surprising! See omnystudio.com/listener https://omnystudio.com/listener for privacy information.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Daniel Whiteson?

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• 2:18Daniel Whiteson?

  Even before we could pry open molecules and see the structure of atoms, we knew there was something fascinating going on. There had to be some kind of internal structure there. Why did we think so? How did we know? Well, because the periodic table is periodic. There are groups of atoms with similar behavior. As you march across column by column, atoms in those same columns have similar behaviors: conductivity, reactivity. That can't just be random. And of course, it isn't. It's because of the structure inside each atom, which was long invisible to us. The structure of the atom is of course dictated by quantum mechanics,

• 2:59Daniel Whiteson?

  which also reveals something about the basic laws of the universe. And now electron structure is a source of torture for high school chemistry students and physics podcast hosts. But it also completely and totally defines our world. It's why metals exist, why things are hard or soft or liquid or solid. It's not magic, but changes to these properties can have dramatic effects on element's behavior and the nature of our experience. And today, we're going to dig deep into what might be the weirdest element on the periodic table. One that isn't just sensitive to quantum mechanics, but to our other great theory of physics: relativity. Mercury, and here I mean the element,

• 3:42Daniel Whiteson?

  not the planet whose orbit was famously predicted by relativity, is very strange because it's liquid at room temperature. It's the only metal we know that is liquid at room temperature, that you can pour without ever heating it up. It's even liquid if you put it on ice or snow. This is knowledge we share with the ancients. The name mercury comes from its Greek name, which I won't try to pronounce, but means watery silver. Why? What is so special about mercury? What is going on inside that atom? Welcome to Daniel and Kelly's extraordinarily chemical universe.

• 4:32Kelly Weinersmith?

  Hello, I'm Kelly Wiener-Smith. I studied parasites and space. And because I was a child of the 90s and we got ourselves into all sorts of trouble, I had a necklace that was a vial of mercury.

• 4:43Daniel Whiteson?

  Oh, no.

• 4:43Kelly Weinersmith?

  And now I'm just glad it never got, like, smashed on me or something.

• 4:49Daniel Whiteson?

  Are you sure it wasn't permeable in some way?

• 4:51Kelly Weinersmith?

  It would explain a lot.

• 4:54Daniel Whiteson?

  Folks, Kelly would be so much smarter if it wasn't for that necklace.

• 4:58Kelly Weinersmith?

  Ouch, ouch.

• 4:59Daniel Whiteson?

  I mean, she's already super smart. I don't think we could handle an even smarter Kelly.

• 5:03Kelly Weinersmith?

  Oh, good cover. I love it.

• 5:05Daniel Whiteson?

  Well, I'm Daniel. I'm a particle physicist, and I'm not a big fan of chemistry, but I am in awe of its influence over our world.

• 5:13Kelly Weinersmith?

  Yeah, I was surprised to see that you picked a chemistry topic, that you did this to us on purpose. And so let's try to focus on positives for chemistry for like, half a second. What was your favorite moment in a chemistry class?

• 5:27Daniel Whiteson?

  Ooh, I remember taking the final and being done with it.

• 5:35Kelly Weinersmith?

  Amazing.

• 5:35Daniel Whiteson?

  No, I was recently talking to the daughter of a friend of mine and asking her what she wanted to study in college. And she said, chemistry. And I said, cool, why? And she said, chemistry is very tactile. It relates to things that are right in front of us. It controls how things operate. It's almost like you can do magic. And she was right, you know, like, particle physics is very cool and reveals the fundamental nature of reality, blah, blah, blah. But it talks about things you can't see, really. And so like, how do you know the electrons are following those rules? Are the quarks are doing this or that? Whereas like, you can see stuff flow or boil or bond or reflect or whatever. It really does determine the nature of our experience.

• 6:15Kelly Weinersmith?

  Yeah, I agree and I disagree. I agree on like, a global level. So I did my senior honors research work in an organic chemistry lab. Because even though I talk about how much I dislike chemistry, I had a lot of chemistry friends and I was kind of into it for a while.

• 6:31Daniel Whiteson?

  Didn't know that about you, Kelly. Hmm, interesting. Recalibrating over here.

• 6:36Kelly Weinersmith?

  I made so many mistakes in the chem lab, though I'm so lucky I didn't die. But you know, I would mix things together and I'd be like, all right, clear liquid mixed with clear liquid and it still looks like a clear liquid. Did I do the reaction I was trying to do? I don't know. And so I know there's a lot of stuff where it's like you can see stuff's happening, but there's also a lot of stuff where you have to just like, expect the thing happened that you thought was gonna happen. And it's, yeah, I don't know. I like fish. You can really see what's going on with fish.

• 7:01Daniel Whiteson?

  You can see fish guts, but you can't see atomic guts. That's the issue.

• 7:05Kelly Weinersmith?

  That's right. That's right. You can't see the backside attack happening in real time. I think that was a chemistry reaction that my friends and I maybe focused on a little bit too much. But anyway, we had some fun.

• 7:16Daniel Whiteson?

  Yeah. Well, you know, underlying chemistry is physics and there's a close relationship between chemistry and like quantum physics that determines the nature of the atoms. And what we're going to discover today is that the answer to the question of the episode might not actually be chemistry. It might be physics after all.

• 7:34Kelly Weinersmith?

  Oh, that's.

• 7:40Kelly Weinersmith?

  I think we just found our video clip for this episode.

• 7:45Kelly Weinersmith?

  You have the right voice for an evil scientist laugh.

• 7:48Daniel Whiteson?

  Wow. Yeah, I'll put that in my next grant proposal.

• 7:51Kelly Weinersmith?

  Okay. So today, we're talking about why mercury is liquid at room temperature. And I didn't know the answer to this before reading the outline. And, you know, to be honest, since it's a brief outline, I still don't think I know what the answer is, but I will by the end of the hour. And so let's see what our audience thinks about why mercury is liquid at room temperature.

• 8:13Daniel Whiteson?

  So think about it for a moment yourself. Do you know the answer? Is it chemistry? Is it physics? Is it some weird combination? Is it physical chemistry? Here's what our audience had to say.

• 8:24Speaker 06

  Just characteristics of that particular element.

• 8:28Speaker 07

  Based off of the chemistry of the item. So this sounds like a will make for a very interesting episode.

• 8:34Speaker 08

  Mercury may not be very good at sharing its electrons and that's why it is a liquid at room temperature.

• 8:44Speaker 09

  I think it's because the amount of energy that's required to break the bonds to turn into a liquid is really low because it's just a bit weak. And yeah, like my son, I think it's because of dragons as well.

• 8:55Speaker 10

  Something to do with its electron orbitals.

• 9:01Speaker 11

  I guess that the heavier the element, the more solid it should be. But mercury is a heavy metal, so this might not be an adequate explanation. Maybe this is related on how the molecules of mercury are formed.

• 9:15Speaker 12

  Because of the way its electrons behave, actually. It has to do with the way that they are bonding or in this case, not bonding. So it's a very weak chemical interaction.

• 9:27Speaker 13

  Maybe it has something to do with how the electrons are arranged.

• 9:31Speaker 14

  I thought mercury was a liquid at room temperature for a similar reason as to why water is as well. How the bonds between the atoms work and interact.

• 9:42Speaker 15

  Mercury is liquid at room temperature because it's solid at a different temperature. A lower temperature.

• 9:50Speaker 16

  I don't really know why metals are liquid at any temperature. I don't know.

• 9:56Speaker 10

  I don't know. Hmm. Now I'm curious. Its valence electrons are paired, which I guess makes it less necessary for it to form the kind of crystal structure that you get in most metals.

• 10:13Speaker 17

  Because its outermost electron shell loses electrons easily and does not form strong bonds.

• 10:22Speaker 18

  Has to do with the specific heat of the substance.

• 10:28Speaker 10

  I knew, I forgot.

• 10:30Speaker 19

  That at room temperature, the chemical bonding between the atoms are weaker than in the cold where they get stronger.

• 10:38Kelly Weinersmith?

  I love the answer that they would love to know this. There are so many amazing patterns in the periodic table. I love that curiosity about chemistry. You and I should maybe try to channel that. A little bit more.

• 10:50Daniel Whiteson?

  I totally agree with that answer. I think it is amazing the patterns in the periodic table. And I love how it reveals the structure of the universe and it is very, very cool. It's just also very complicated. Wow. It's not easy. So, you know, my fear of chemistry is mostly in awe of the people who can do it because I can't.

• 11:10Kelly Weinersmith?

  I found it very difficult. Mostly I was spilling the chemicals on myself or dropping the glassware. But my favorite moment in chemistry actually was the very first college chemistry class I took, where we got the melting point and some other features of some unknown substance. And by calculating these different features of the unknown substance, we were able to figure out what we had been given. And that felt like amazing, like forensic science, CSI sort of stuff. And I just loved that. So I have a soft spot in my heart for calculating melting points, which is maybe not something I imagined I'd be saying when I was a kid. But I've never been cool, so I'm leaning in. So Daniel, what determines melting points?

• 11:51Daniel Whiteson?

  Mm hmm. Yeah, this is very cool, you know, that we even have melting points for stuff, that things have phases. I think phases are super fascinating. You can have like the same set of atoms and at a slightly different temperature, they're dramatically different behavior, right? This is not like a smooth transition where it's like kind of mushy and then kind of gassy. It goes from like solid to flowy, you know? It's really incredible that phases even exist. And I just want to nerd out about phases for another minute before we dive in, because phases are a much more general concept in science and in physics than just like the state of matter. We use phases to describe any time there are a set of equations that have limited applicability.

• 12:33Daniel Whiteson?

  Like you could talk about Newton's equations for the motion of stuff, apply to a certain phase of matter when things are not very massive and not very fast. It's like the Newton phase of mechanics. So I think it's really a fascinating concept because it admits that all of our laws are limited the way that like the laws of fluid mechanics only apply to fluids and the laws of crystal lattices only apply to crystals and not to everything. So anyway, I think that's sort of deep and philosophical.

• 13:00Kelly Weinersmith?

  I think I'm not following. All of the things that you just said still sound like you're talking about phases. So you said something about like how fast something's moving. And to me, that makes me think about, you know, the transition from a liquid to a gas or something. I think I'm missing the point.

• 13:13Daniel Whiteson?

  No, you're right. And they're all linked to like the behavior of the stuff. But you know, think about like the very early universe. We think there was a time when things were so hot and so dense that even our laws of quantum field theory might not apply. So there's like a phase in the universe when quantum field theory applies. And there's a phase when it doesn't apply, right? Because it's not like a fundamental theory of everything. It's an approximation that only works under some conditions. In the same way, like the laws of the liquid phase of water only work when water is liquid. They don't work when water is solid or when water is a gas. All of our laws are approximate that way and only work in a certain phase.

• 13:49Kelly Weinersmith?

  Okay, right. So when I was in my Goth phase, the only thing that worked for me was black clothing.

• 13:54Daniel Whiteson?

  Exactly.

• 13:54Kelly Weinersmith?

  And I get it. Phase is a more general word. Okay, moving on.

• 13:59Daniel Whiteson?

  So what's happening here, the listeners were right. Things melt when the bonds between them loosen, right? So a solid often is a crystal. You have like these pieces click together into a crystal lattice. Not everything ends up like a crystal, you know, glass, for example, is like a big disordered mess. But lots of things click together to form a crystal. And you can imagine like the Lego pieces snap together and it's very solid. It acts like a big chunk, right? And that happens because there are bonds between them, right? These things don't just click together physically. It's not like you're just physically sharing the space. They are connected to each other. They are bound together because of what their electrons are doing. So if you have strong bonds between stuff and the stuff doesn't have a lot of energy, can't wiggle around a lot, then it clicks together to form a solid.

• 14:43Daniel Whiteson?

  Now heat that stuff up, give it energy, make those atoms wiggle and jiggle and zoom. If they have enough energy to overcome the power of those bonds, then they will break open that crystal lattice and they will slide around. And that's how they become a liquid. That's what melting is, is breaking down the crystal lattice so that the atoms are more loosely bound to each other. They're still connected. There's still some bonds there. It's not totally a gas. A gas is when you give up all connection to each other and they're all just a bunch of independent molecules or atoms. So liquid is when you break those strongest bonds and now you have very weak bonds so that the atoms can flow over each other.

• 15:18Kelly Weinersmith?

  Is it just that like some percent of the bonds have broken or that bonds of a certain type have broken, like all the hydrogen to oxygen bonds have broken, but the carbon to hydrogen bonds haven't broken yet? Or does it depend on the molecule that you're talking about?

• 15:32Daniel Whiteson?

  It depends on the molecule, but it also depends on the type. And so, for example, after the bonds are broken, there are still some bonds there, but they're weird, very soft intermolecular bonds. You know, you can have like a bond between this water molecule and that water molecule because of its polarity. Like maybe they're overall neutral, but it's got a little bit more negative on this side, a little bit more positive on that side, and that can attract the neighboring atom, or they can organize themselves that way. It was sort of a loose bond. Whereas when they're tightly bound, then they use a different kind of bonds. You know, the electrons can like literally be shared among them. And some kind of lattice is like in metals, the electrons just flow freely, right? You can't even really say which atom they're connected to. They just like flow all around the whole thing. You have really complex energy level structures for those electrons because they're really

• 16:17Daniel Whiteson?

  just shared. It's like one really big atom or one super molecule.

• 16:22Kelly Weinersmith?

  You know, you and I might both know more chemistry than we've been letting on. Secrets coming out today.

• 16:28Daniel Whiteson?

  That's solid state physics.

• 16:30Kelly Weinersmith?

  Okay. All right. I was getting worried there. Okay.

• 16:34Daniel Whiteson?

  So it really is about the strength of the bonds. If atoms are capable of making very strong bonds, then it requires more energy to break them, higher temperatures to break them. So stronger bonds between the atoms mean a higher melting point. If there are already very, very loose bonds between the atoms, like the atoms don't like to bond at all, or they use none of the very strong categories of bonds, then the melting point is going to be lower because it doesn't take a lot of energy to release the atoms. So we're going to take several steps towards the understanding. The first one is melting point is determined by the strength of the bonds. Stronger bonds, higher melting point. Weaker bonds, lower melting point.

• 17:11Kelly Weinersmith?

  Okay, I've got that general concept. Can you give me a little bit more information about what makes for a strong bond?

• 17:16Daniel Whiteson?

  Yeah, so you're basically you're asking like, well, what makes the bond stronger? What makes the bonds weaker? Why does it depend on the element? What determines that? And the answer there is the electron structure. The electrons are the things that do the bonding. And so the electron structure is what determines whether the bonds are strong or whether the bonds are weak. For example, one of the most important thing is have the electrons filled up their shells? Like the electrons form these shells around the atom. You know, there's the first energy level, the second energy level. If that outermost energy level is filled, then the electrons in the atom are pretty happy and they don't want to go anywhere. If however, they're not filled, you have like four out of eight or seven out of eight,

• 17:57Daniel Whiteson?

  then that atom is happy to take another electron or to share another electron with its friend. So together they have filled shells. So for example, if you have hydrogen, hydrogen could have two electrons in its outer shell, but it's only got one. So it likes to find another hydrogen. So together they have two, they can share those two in a bond. So those two electrons are shared between the two protons and that thing is really bound together into H2.

• 18:23Kelly Weinersmith?

  Aww.

• 18:25Daniel Whiteson?

  I know, it's very cozy.

• 18:28Daniel Whiteson?

  Actually, what if they hate each other? What if they're like, oh my God, this guy never does the dishes?

• 18:32Kelly Weinersmith?

  Oh, I get that. I get that, but they can't get away from each other. Well, you gotta turn up the heat so that they can escape.

• 18:39Daniel Whiteson?

  Ooh, melting is like chemical divorce. Wow, fascinating. We are liberating these atoms. You've heard of women's liberation, now we're doing proton liberation.

• 18:48Kelly Weinersmith?

  I thought it was electron liberation.

• 18:50Daniel Whiteson?

  There you go, yeah, electron and proton, yeah.

• 18:51Kelly Weinersmith?

  Oh, okay, got it, yeah.

• 18:53Daniel Whiteson?

  So there's a few things that affect whether these bonds are strong or not. One is, are the shells filled, right? So do you have a complete outer shell? It's like a set of armor, it's hard to penetrate? Or do you have an incomplete outer shell? In which case the atom likes to bond. And we're going to go through some examples later on. You'll see that these patterns emerge in the periodic table. The other is, how closely is it holding on to those electrons? Because the electrons can be like really far out in sort of a distant outer shell. Very weakly held, or they can be like really tightly held. If the atom is very, very powerful, it has like a lot of protons in it, it can really hold those electrons close. So that also determines this. So we sort of like two dimensions here to determine whether the bonds are strong or whether the bonds are weak.

• 19:39Daniel Whiteson?

  Is it filled shells? Is it not filled shells? So filled shells means harder to form bonds, not filled means easier to form bonds. If the electrons are close, it's harder to form bonds with them because they're held tightly by their nucleus. If the electrons are not close, it's easier to form bonds.

• 19:55Kelly Weinersmith?

  This is reminding me of the fun conversation that we had in response to a listener question about why life tends to be carbon based instead of silicon based.

• 20:03Daniel Whiteson?

  Yeah.

• 20:04Kelly Weinersmith?

  Silicon, not silicone. I always mix those two up.

• 20:07Daniel Whiteson?

  In Orange County, it's silicone mostly, actually.

• 20:09Kelly Weinersmith?

  Yeah. Well, I live in Virginia where, anyway, we don't need to go there. And the answer ended up depending on a lot of these questions.

• 20:17Daniel Whiteson?

  Yeah, but you're putting your finger on a really important trend, which is that as you go across the periodic table, elements in the same column tend to have the same electron structure, right? They have like one extra electron or two, or it's totally filled or it's not, right? So the rows in the periodic table reflect the energy levels. And then as you march along the columns, you have the same pattern of the electrons filling up. So you go from left to right in the periodic table, you're filling up that outer shell. And so, for example, the last column in the periodic table all have their last one all filled up because it's the last one. And so that whole column are folks with very filled shells. That's why they're called the noble gases. They don't like to interact with anybody.

• 21:01Daniel Whiteson?

  And that's why they're all in the same column, because they have the same electron structure, which is why they have the same kind of behavior. And like the first column, all are noble gases plus one. So they all have one extra electron, one lonely electron in its own last shell, really dying to do something with its friends. And so that's why those are all very active. For example, they like to react and interact. So the electron structure really determines all these properties and the periodicity of the table.

• 21:27Kelly Weinersmith?

  Now, I remember sitting in chemistry in high school. And being like, all right, I think maybe I have finally memorized how many electrons are supposed to be in each one of these shells. But why are there shells in the first place?

• 21:40Daniel Whiteson?

  Yeah.

• 21:40Kelly Weinersmith?

  And I never got a satisfactory answer. And maybe that's why I never could love chemistry until this moment, Daniel. Because I'm gonna ask you, can you tell me, why are there even shells?

• 21:53Daniel Whiteson?

  And do they sell them by the seashore, right? Yeah, so the answer is, of course, the underlying physics, quantum mechanics. Like, let's start with a simple atom like hydrogen. Hydrogen has a proton and it has an electron. Where could that electron be? Well, quantum mechanics says, use the Schrodinger equation. And Schrodinger equation says, well, there's a bunch of solutions for where the electron could be, a bunch of places where everything is copacetic and the wave function is happy. But there's a ladder of solutions, not a continuous state of solutions. Like, let's zoom out and take a classical example where we have intuition. The orbit of a planet. Where can a planet orbit the sun? Well, classical mechanics says, if you have a certain radius, you need to be moving at a certain velocity in order to have a stable orbit. Cool, but every radius has a velocity.

• 22:38Daniel Whiteson?

  Like, you could orbit the sun at literally any place. There's an infinite number of available radii. Once you pick a radius, you have to have the right velocity, or you'll fall out of orbit, or you'll zoom out of the solar system. But you could pick any radius, any solution works. Around hydrogen, that we like to think of these as planetary orbits, and there's lots of misleading upside diagrams that convince you so, these are not orbits, right? These are solutions to the Schrodinger equation, and there's a ladder of solutions. There's a finite number. There's like, number one, number two, number three. The quantum mechanics dictates that. And an intuitive way to think about why there are a discrete number of solutions is to think about how the wave function fits around the atom. It goes around the atom, it has to reinforce itself. So when you go around, you have to come back and basically be in the same part of the

• 23:23Daniel Whiteson?

  wave. And so you can fit like, one wave, or two waves, or three waves. We have like, 3.7 waves, then it's going to interfere with itself, and it's not going to be a stable solution. So you want a stable solution of the electron around the atom, you have to fit a certain number of wavelengths of the wave function around the atom. So that's why you have a discrete number. That's what causes the shells. And then it gets much more complicated if you have more protons and multiple electrons. I mean, you get all the way up to like, Mercury, it's a mess.

• 23:52Kelly Weinersmith?

  So, does it have to be waves? Because electrons aren't point particles, they're actually waves, and that's where the wave thing comes in?

• 23:59Daniel Whiteson?

  Yeah, exactly. You have the wave function, which is a complex value thing. And it is really the thing that tells you where the electron can be. And so when the electron is in its lowest state, you shouldn't think of it like, oh, it's orbiting at a certain radius. It's got a probability distribution, and that's the minimal stable configuration for that state.

• 24:18Kelly Weinersmith?

  Okay, all right, got it. Chemistry is awful. That's what I think.

• 24:22Daniel Whiteson?

  The other crucial piece of physics is that electrons have this weird behavior where you can't have two of them having the same state. They just will not share. You know, they're like grumpy siblings. You cannot put two of them in the same bed. You need to have different rooms, or they need to have something different. So the first state, you can have two electrons because one can be spin up and one can be spin down. The second layer has more energy, so they can wiggle in different ways. There's different patterns to how their energy is distributed. So there's more options there. But quantum mechanics tells us that we can only have one electron per unique energy level. And as the shells get bigger, there's more options for the electrons, for ways to differentiate themselves. So you can have two in the first one, and then I don't even remember the numbers, and I'm not going to guess.

• 25:07Daniel Whiteson?

  But yeah, it gets very complicated. But there are quantum mechanical answers for why there are a certain number of electrons allowed in each shell. It has to do with the polyexclusion principle and the number of ways you can distribute the angular momentum solutions in each energy level.

• 25:22Kelly Weinersmith?

  In my head, at some point, the number of electrons in the shells, as you added shells, started being the same. But I took chemistry when I was, gosh, that was over 30 years ago now. So that's just a bad memory, right? It's the number of electrons in each shell gets progressively higher the farther you get from the center?

• 25:41Daniel Whiteson?

  Yeah.

• 25:42Kelly Weinersmith?

  Okay, all right.

• 25:43Daniel Whiteson?

  But the shells then start overlapping. And you know, sometimes like the highest energy subshell from level four is actually higher energy than the lowest energy subshell from level five. So level five fills up before the last level four fills up. And the ordering starts to get really, really nasty, which is why electron configurations are hard.

• 26:03Kelly Weinersmith?

  I'm feeling angry.

• 26:06Kelly Weinersmith?

  Why is it like that? All right, all right. Let's give ourselves a chance to release the anger. And when we get back from this commercial break, we'll take another peek at the periodic table and look for patterns and melting points.

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• 28:37Kelly Weinersmith?

  And we're back. Okay, so at the beginning of the show, we talked about where you find electrons, how they fill up the shells, and how that impacts bonds between atoms. Now, we're going to take a look at the periodic table, because we're really interested in melting points to try to figure out why mercury is weird. So let's look for patterns in the periodic table to see what we should expect mercury to be doing in terms of melting points.

• 29:01Daniel Whiteson?

  Yeah, there's a lot of really interesting stuff to dig into here, and a lot of it can be explained by chemistry. But mercury sticks out like a sore thumb. And so we're going to walk you through a couple of the trends that explain what's happening in the periodic table. But they can't completely describe mercury, and they're not actually enough to make mercury liquid at room temperature. So there's a little bit of physics we're going to need at the end to give you that complete explanation.

• 29:25Kelly Weinersmith?

  Chemistry is never enough.

• 29:28Daniel Whiteson?

  Chemistry is never enough. So let's keep in mind that we're thinking about the electron structure of these elements, whether or not, for example, they have a filled shell. And so let's like walk across the middle of the periodic table. So you have Sc, which is scandium, right? And then the next one is titanium, and it goes all the way across to copper and then to zinc. And if you look at the melting points here, they start pretty high, like scandium melts at 1500 Celsius. And then they go down to zinc, which melts at only 400 Celsius. Now, that's pretty high. You don't want to get into like a hot tub of zinc. But it's a big difference. It's like more than 1,000 degrees difference. Why does scandium melt at a really high temperature? And zinc melts at a really low temperature?

• 30:12Daniel Whiteson?

  Because zinc is the end of this chunk of the periodic table. It's completed a shell. So zinc has a complete shell, which means it's not as likely to bond. It's not as easy for it to bond, which is why it has a lower melting point than all of its friends next to it. Like copper, right next door to zinc, has a melting point of more than 1,000 degrees C, whereas zinc, again, is just 400. And you see the same behavior in the next row. Silver, which is right next to cadmium. Cadmium is just under Zinc, silver has a melting point of about 1,000 C and cadmium of about 300. So just this one step over, you add one proton and one electron, melting point drops precipitously.

• 30:55Daniel Whiteson?

  And the reason is that you've filled up this shell. Now these atoms can't form the same kind of strong bonds where they're sharing electrons with each other. And so it's much easier to break them apart. So that's why zinc and cadmium and mercury, which is also in this column, have much lower melting points than their friends, copper, silver and gold, which are right next to them in the periodic table.

• 31:16Kelly Weinersmith?

  They're more stable and because they're more stable, it's easier to make them liquid?

• 31:21Daniel Whiteson?

  It's easier to make them liquid because their bonds are weaker. It's not about the stability. These aren't like radioactive elements. It's just like, do they like to click together? And zinc and cadmium and mercury all have a completed last shell. It's the S2, the 4S2, the 5S2 or the 6S2. They've completed that little subshell and so it's harder for them to form bonds. Like copper and silver and gold, the ones next door to them, are missing one electron relative to our friends zinc, cadmium and mercury. So they'd like to fill in that last shell. And if they meet another atom of their type, like two silver come together, they can complete that last shell together. And so they can form this kind of strong bond by sharing electrons. It's harder to break them apart. Mercury can't do that. Cadmium can't do that.

• 32:06Daniel Whiteson?

  Zinc can't do that. So they can't form the same kind of strong bond between the atoms. And so it's easier to break them apart, which means a lower melting point.

• 32:15Kelly Weinersmith?

  Got it. Okay. Thank you.

• 32:17Daniel Whiteson?

  So now we're comparing these two columns, right? Column 11 has a higher melting point than column 12, zinc, cadmium and mercury. But still mercury looks weird. Like zinc and cadmium melt at 300, 400 C. It seems like a very respectable temperature for a metal. Mercury melts at negative 39 C. Like mercury has a crazy low melting point, right? To make mercury solid, you have to get it to negative 39 Celsius. That's very, very cold, right? And it's a huge jump. And if you're saying, all right, well, this column is all colder than the other one, still within the Column zinc and cadmium have a higher melting point than mercury. So what makes mercury so much lower than zinc and cadmium?

• 33:01Daniel Whiteson?

  Well, there is a trend there that we would expect. As you go from top to bottom in the column, you're getting heavier and heavier nuclei. Right? Like mercury has more protons than cadmium, which is more protons than zinc. And that's the other effect we talked about. Mercury holds on to its electrons more tightly than cadmium or zinc because it has more protons. Say you're an electron floating around the atom. There are more protons pulling you in, binding you tightly to that atom. If you're mercury than if you're cadmium or if you're zinc. Does that make sense?

• 33:35Kelly Weinersmith?

  Kind of. So if you're mercury, though, you also have more electron shells. And so your outer shell, which would do the bonding, is farther away from your heavy nucleus. They're farther away. What does that do?

• 33:50Daniel Whiteson?

  Yes, exactly. And this is my frustration with chemistry. It's that you can often tell yourselves these intuitive stories and then somebody can come along with another intuitive sounding story that also makes sense. And you're like, hmm, hmm, I don't know which one of these is right. You know, and the answer is that it's complicated. But overall, the fact that you have more protons wins. And so it pulls these things in. And you know, the way to think about it is like, yeah, these things can all be neutral. You have an equal number of protons and electrons. And the electrons don't like to be on top of each other. But still, these protons are very powerful and pulling them in. And each electron is having basically just a relationship with the protons, not with the other electrons. It's not like the power of those protons is shielded by the other electrons. Instead, it's now pulled in by 80 protons.

• 34:35Daniel Whiteson?

  Right? So it's a very powerful force. I think that one wins. But hey, chemistry experts out there, write in and tell me if we got that wrong.

• 34:42Kelly Weinersmith?

  Okay, so mercury really wants to be a liquid. And we know that because it has a full shell and it's really big. But even knowing those two things, mercury wants to be a liquid at temperatures way lower than what we would have expected. So where do we go next to try to understand that?

• 35:03Daniel Whiteson?

  Yes, so we're at the limits of chemistry here. Chemistry tells us, yes, mercury should be lower than gold, for example, in the same way zinc should be lower than copper, and it is. And chemistry tells us, yes, mercury should have a lower melting point than cadmium or zinc, because it's a bigger atom and it holds these things in. And that's all cool. But if you run the calculations and you take all that into account, chemistry predicts that mercury's melting point should be 82C. But the measured value is negative 39C, more than 100 difference. So like, yes, there are these trends that suggest mercury should have a low melting point, but they suggest it should still be solid at room temperature. To get mercury even lower, to get that melting point down below room temp, and even down

• 35:46Daniel Whiteson?

  below 0C, you need to do something else. Chemistry is not enough to make mercury liquid.

• 35:52Kelly Weinersmith?

  Come on, chemistry, get better with your predictions. This isn't physics.

• 35:57Daniel Whiteson?

  So you might think, well, is quantum mechanics wrong? Because chemistry is determined by quantum mechanics. We just told you about all the shells and the Schrodinger equation and all this stuff, right? So is quantum mechanics wrong? Well, quantum mechanics by itself is not wrong, but it's not the whole story, right? We know that quantum mechanics doesn't describe the entire universe, because quantum mechanics, for example, can't describe gravity, or black holes, or the beginning of the universe. We have another theory in physics that helps us explain what happens when things go really, really fast, or when things get really, really massive. That's relativity. All the calculations we've been doing, all the explanations we've been giving are chemistry based on quantum mechanics that assumes that relativity is not a thing. If, for example, assumes that there's no limit to how fast things can go,

• 36:42Daniel Whiteson?

  or that there are no black holes. We're essentially ignoring relativity and doing pure quantum mechanical calculations. And most of the time, that's fine. Relativity is not really relevant. We're not doing chemistry around a black hole. We're not doing chemistry near the speed of light. So it works. But, you know, sometimes it doesn't. And that's what's happening here is that we've been ignoring the relativistic effects on the electrons of mercury.

• 37:05Kelly Weinersmith?

  And that's because everywhere there's mercury, there's actually a tiny black hole next to it. Is that right? No? No. Okay.

• 37:14Daniel Whiteson?

  No, but you know where you can get your mercury?

• 37:16Kelly Weinersmith?

  At the flea markets I went to as a kid.

• 37:18Daniel Whiteson?

  No, in HG Wells.

• 37:20Kelly Weinersmith?

  Oh, grown.

• 37:25Kelly Weinersmith?

  No, that was great.

• 37:27Daniel Whiteson?

  No, it was not great, but thank you anyway. Yeah. So what's happening here is not that there's a black hole next to every bit of mercury, although I love the theory, I don't know if you heard it, that maybe every electron actually is a black hole. Could we tell anyway? We'll have to talk about that on the podcast another time. No, what's happening here is that electrons are actually relativistic around mercury. Mercury is so powerful with its nucleus, those 80 protons have such a strong hold on the electron that the electron velocities start to approach the speed of light. They're not going at like 99% the speed of light, but whereas electrons around hydrogen go about 1% of the speed of light, electrons near mercury move almost 60% of the speed of light, which is close enough for these relativistic effects to start to matter.

• 38:13Kelly Weinersmith?

  So that suggests to me then that everything with 80 protons or more should also have these relativistic effects. Is that true? From there on out, we need relativity to understand the melting points of atoms?

• 38:26Daniel Whiteson?

  Yes, absolutely. And there's another guy under mercury in the periodic table, coppernissium, which is a crazy synthetic chemical element, which means we need to make it. It's not like found naturally in the wild. And people suspect that the relativistic effects for coppernissium are even stronger than for mercury. Mercury is something that's all over the place, so it's well studied and easy to play with, but turns out doing these calculations, including the relativity in our calculations, is very hard, which is one reason why only a couple of years ago were people able to do this calculation and predict the relativistic corrections to the original quantum mechanical calculations.

• 39:03Kelly Weinersmith?

  Say that again, this time in English.

• 39:06Daniel Whiteson?

  So you can go out and measure the melting point of mercury, right? You put it on the table, you heat it up, you see it melt, you cool it down, you see it solidify. That's the measured value. Then you can go and say, I'm going to predict what it should be based on my understanding of what's happening. And they can do calculations and they do these calculations, like we referenced earlier, a number of 82C. That comes from using quantum mechanics to predict the strength of these bonds and understanding like at what temperature those bonds would break. So you're using quantum mechanics to predict the bonds and from there you can get the temperature. So that's the predicted value of mercury. Now, if you go in and you say, well, I'm going to tweak quantum mechanics because I'm going to do quantum mechanics not by itself, I'm going to include relativistic effects in my quantum mechanics, then you're changing what's going on in your predicted

• 39:51Daniel Whiteson?

  mercury, which changes the prediction of the bonds, which changes your prediction for the melting point. And so when we see a difference between our prediction and our observation, we know something is wrong. So we go back and tweak our predictions to make it right. And you know, in principle, we should always be using relativity to get everything right. But most of the time, it's irrelevant. You want to calculate when that train is going to go from Cleveland to New York, relativity doesn't have any impact, right? So you can ignore it. Also, relativity is a huge pain. Like, it's nonlinear, it's complicated, it's not easy to do. So most of the time, if you can't ignore it, you should. But when you discover that your non-relativistic calculations are not up to the task, when they're getting the answer wrong, that's when you got to go back and do your homework

• 40:33Daniel Whiteson?

  and include the physics in your calculation, because it turns out it's necessary.

• 40:38Kelly Weinersmith?

  Beautiful. Okay, all right. So now we've got electrons moving super fast. And now we're incorporating relativity. What is the jump from there to understanding why melting point is affected?

• 40:50Daniel Whiteson?

  Yeah. So first, we should clarify which part of relativity we're including, because folks might be thinking, Daniel's been telling us that quantum mechanics and relativity can't play nice together. Like, that's the whole goal of modern physics, is come up with quantum gravity and understand the early universe and blah, blah, blah, and string theory.

• 41:06Kelly Weinersmith?

  That's right. Daniel has been telling us that.

• 41:10Daniel Whiteson?

  And that was not a load of baloney. That's all true. That refers to our failure to unify quantum mechanics with general relativity, the theory of gravity and curvature and all sorts of crazy stuff, which we have not been able to do. But we have, and it's been decades and decades since we've done this, unified quantum mechanics into special relativity, the theory of what happens when things go near the speed of light and incorporates the fact that light is always the same for all observers and that nothing can go faster than light. Special relativity, which is just like flat space, but includes things like time dilation and length contraction and maximum speeds and weird velocities and stuff. That's special relativity that we have been able to merge with quantum mechanics. We have relativistic quantum mechanics that allows us to do these calculations.

• 41:54Daniel Whiteson?

  Or quantum field theory also has special relativity built in. So special relativity and quantum mechanics do play very nicely together.

• 42:02Kelly Weinersmith?

  Aw, that's great.

• 42:06Kelly Weinersmith?

  Okay, and so when they're playing together, why does them playing together change melting points?

• 42:11Daniel Whiteson?

  Yeah, great question. And since this paper came out, there's been a lot of coverage of this result in popular media. And I read all of them, and they're all wrong.

• 42:20Kelly Weinersmith?

  What?

• 42:21Daniel Whiteson?

  They all get the physics wrong.

• 42:24Kelly Weinersmith?

  Let's take a break. And when we come back, you're going to tell us how we get it right.

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• 44:41Kelly Weinersmith?

  Before the break, Daniel was telling us that he's been reading a bunch of pop-sight articles that attempt to merge quantum mechanics and special relativity, and that all of their explanations are wrong. So let's talk about the wrong explanations first.

• 44:54Daniel Whiteson?

  Yeah, and these are not just pop-sight articles in like, you know, sciencenews.buzz or something.

• 45:00Kelly Weinersmith?

  I hate sciencenews.buzz.

• 45:04Daniel Whiteson?

  People are constantly forwarding me articles from sites with names like that and be like, is this true? And I'm like, man, why are you even reading that site? You know, but there are some pretty venerable places that have put out press releases and articles about this that get it wrong. And they all repeat the same nonsense. They all repeat this business about how electrons, when they approach the speed of light, gain mass, become more massive. That's the heart of their explanation. And number one, that's not true. Things do not gain mass as they approach the speed of light. This concept of relativistic mass is outdated. It's not appropriate. It was Einstein's mistake. We talked about it recently on the podcast.

• 45:43Daniel Whiteson?

  We can dig into it again in a moment. Also, it doesn't really explain why mercury has a lower melting point. You know, electrons having more mass doesn't answer this question. I actually reached out to a chemist here at UCI to ask him about this. And he said, quote, "Most chemists know little about relativity, and I suspect that makes them more likely to swallow the popside buzzwords."

• 46:08Kelly Weinersmith?

  Oh, I'm surprised any chemist was willing to talk to either of us, given our reputations.

• 46:14Daniel Whiteson?

  Well, maybe he's not a listener to the podcast. So let's unpack that for a minute. Why do I say that it's not true that electrons increase their mass? Because you hear that everywhere, right? And it's a very popular thing to say because it sounds weird. It's one of these things that people say a lot because it has an impact on your mind, but doesn't really actually make sense. It just sounds cool. And we talked about on the podcast why that doesn't really make sense and why relativistic mass isn't even a useful concept. It doesn't make sense because if mass depends on velocity, velocity is three directions, right? It's a vector. You can have velocity in one direction, another direction, a third direction. There's three dimensions of space, three dimensions of velocity. If mass depends

• 46:55Daniel Whiteson?

  on velocity, then mass also has three dimensions. Then you would have like a different mass in each direction. It's weird. It doesn't make any sense. It's not what we think about as mass. And mostly, it's misleading. People think that something weird and mystical is happening, like as the electron is approaching the speed of light, it's growing in mass, like it's getting more stuff to it in some weird way. That's not what's happening at all. What's happening instead is that as electrons approach the speed of light relative to an object, our intuition about the relationship between energy and velocity fails.

• 47:29Daniel Whiteson?

  Down here at very low velocities at the surface of the earth where we're running around at low speeds and driving, and what we think are high speeds were really pretty slow compared to the speed of light. We think that as you add energy, velocity goes up too, and they go up together, right? But what happens as you approach the speed of light is, energy can keep going up. There's no limit to energy, but a velocity is limited to the speed of light. And so, as you add energy to something, its velocity doesn't go up by as much. And so, that sounds sort of like, oh, it's getting more massive because it's harder to get it to go faster, right? It's really just a relationship between velocity and energy that gets more complicated near the speed of light. So, it's not like a useful thing. It's, we can just use energy. Energy contains all the same information as relativistic

• 48:14Daniel Whiteson?

  mass. And energy is not as misleading. It doesn't give people the impression that like the electron's getting more stuffed to it somehow. So, it's not a useful concept, and it's misleading. And in this case, it doesn't explain why Mercury would have a lower melting point. You know, having more mass would mean it would take more energy to get you to higher velocities, but these things are moving at very, very high velocities. So, that would imply that they have even more energy, which would push them out from the center. It would be easier for them to nab by other atoms. And so, it sort of goes in the wrong direction as far as I understand it.

• 48:52Kelly Weinersmith?

  All right. So, I am definitely not going to be reading science.buzz, or what was it, sciencenews.buzz? Because they clearly got this wrong. And you know, you mentioned that everybody was talking about it. And you know, when my daughter came home from school and was like, electrons increase their mass as they approach the speed of light. I was like, I'm so disappointed in you, Ada. But so, what is the right explanation?

• 49:13Daniel Whiteson?

  So, there is an explanation. It's not like as simple and as compact a story as the electron gets weirdly massive. The answer is that to figure out where the electrons go, you have to solve the equations. And the equations depend on a lot of stuff. And the solutions to those equations, you know, the energies that the electrons are happy to be at are different if you include relativity than if you don't. And if you include relativity, you get electrons with smaller orbits, right? They're still moving at very, very high speeds, but they have tighter orbits. They're closer to Mercury. Essentially, they have lower energy than without relativity. And so, they have tighter orbits at these very high velocities.

• 49:56Daniel Whiteson?

  And because they have tighter orbits, Mercury is able to hold on to these electrons even more tightly than its friends in the same column, zinc and cadmium, for example. And so if you turn off relativity, then it relaxes a little bit and these electron orbitals get larger. If you turn on relativity, then the electron orbitals shrink a little bit. And I went back to that chemist and I asked him, hey, do you have an intuitive explanation for what's going on here? Like, is there a nice little story in the same vein as like, hey, electrons get more mass, but actually correct?

• 50:28Daniel Whiteson?

  And he said, look, chemistry is complicated. And the answer is no, there isn't a nice, simple explanation. It's just that when you include these effects, the first order relativistic correction, if you're doing perturbation theory, is to reduce the energy of this shell. And it turns out to be a really hard calculation, which is why people only recently were able to do it. You have to model a bunch of atoms all together to figure out the bonds between them and all of the electrons around those atoms. And this is a really hard thing to do. You need really powerful computers. And then adding the relativistic pieces means every time you want to move your system forward in time, you have to do a bunch more complicated calculations, like relativity makes everything harder. Like, not only is it harder to think about, but it's also harder to get our computers to predict.

• 51:11Daniel Whiteson?

  There's like more steps in each calculation, more multiplications and divisions and square roots and all sorts of really weird stuff. But it's these relativistic effects which push the prediction from chemistry down below room temperature. So there's a recent paper and they predict that the melting point of Mercury should be negative 23C. So without relativity, they predict 82C. With relativity, they predict negative 23C. Now, the real value is negative 39C, so they're still not getting it right. There's still more to understand there, probably second, third order relativistic corrections, more detailed, accurate predictions. But they have gotten it down below room temperature. And so this, we're convinced, is the explanation for why Mercury is a liquid at room temperature.

• 51:56Daniel Whiteson?

  It's relativity.

• 51:58Kelly Weinersmith?

  So that is super cool. So Mercury has an atomic number of 80 and it's got a really low melting point. But why doesn't everything past 80 also have a really low melting point? It still feels like Mercury is anomalous. Relative to everything else.

• 52:16Daniel Whiteson?

  Yeah, well, it sort of does. Like, if you keep going, you know, lead, for example, has a melting point of 320. That's not that high. It's a lot lower than silver and gold. And that's because it's really heavy and it has these relativistic effects. But also, it doesn't have a complete shell. So it's much higher than mercury because it doesn't have a complete shell. If you get all the way over to the end of the periodic table, you have like xenon, its melting point is like negative 100 C. And radon is like negative 70 C. These things are gas at room temperature. So you see those effects as you move down the periodic table, melting points are shrinking. And one of these reasons is relativity. But it's not the only thing that's happening, right?

• 52:56Kelly Weinersmith?

  Okay, so it's the combination of the shells being filled, how tightly those shells are held by the nucleus being heavy, and the fact that that heavy nucleus is causing the electrons to move faster. Now you have relativistic effects. And all three of those things come together with mercury to impact its melting point more than anything else. So like, for example, if you move to tin, tin, yes, still has that relativistic effect going on, but now you have one electron in the outer shell. And so it's wanting to react to stuff. And so now you're in a different world altogether. And that's why it doesn't have such a low melting point.

• 53:33Daniel Whiteson?

  I think maybe you're thinking about thallium, which is the next one over from mercury. And it looks like tin, but it's actually a TL. But yes, otherwise, yes, exactly.

• 53:43Kelly Weinersmith?

  Yeah.

• 53:43Daniel Whiteson?

  And so that's why thallium is like 350 degrees higher melting point than mercury, because it's got this one extra electron, which would be very happy to bond with other thallium atoms.

• 53:54Kelly Weinersmith?

  My annual eye appointment is next week. And so maybe in a few weeks, I'll be able to read the periodic table.

• 54:00Daniel Whiteson?

  But even if it was TI, that wouldn't be tin. Tin is SN, right? Because it's got some weird Latin name.

• 54:05Kelly Weinersmith?

  Oh, how embarrassing. How embarrassing.

• 54:08Daniel Whiteson?

  But you're right that there are relativistic effects all over the bottom of the periodic table. For example, gold, why is gold beautiful and gold colored? Whereas silver, which has the same electron structure and is one above it in the same column, is basically colorless. It's silver. The answer is relativity. The color of an element depends on the photons it will emit and absorb, which depend on the spacing between the energy levels. And relativity changes those energy levels in gold much more than they do in silver, which makes it gold colored. Without relativity, gold would look like silver.

• 54:46Kelly Weinersmith?

  Oh, my gosh.

• 54:47Daniel Whiteson?

  I know.

• 54:47Kelly Weinersmith?

  So much cool stuff happening with relativity.

• 54:49Daniel Whiteson?

  People always say relativity is beautiful. Now you know why. It's gold.

• 54:53Kelly Weinersmith?

  People are always saying that, like it's common on T shirts and stuff like that.

• 54:57Daniel Whiteson?

  People are saying that. You're being ironic, but I'm not. Relativity really is beautiful.

• 55:02Kelly Weinersmith?

  I do think it's beautiful. I do. And this has been super cool. So how recent is this incorporation of special relativity into our understanding of what's happening in the periodic table? Is this something? I think I'm remembering you said we've kind of known about it for a while, but haven't been able to calculate it until recently. Like, how recently have we started incorporating this stuff in there?

• 55:21Daniel Whiteson?

  So, you know, we've known about quantum mechanics for about 100 years and relativity for about 100 years. They emerged together into relativistic quantum mechanics only a few decades after the birth of both those theories. So that's been for a long time. But in order to do this, calculation requires a lot of computing. So it was only about 10 years ago that people were able to do this calculation and predict the melting point of mercury more accurately than 82C. And so, yeah, this is a pretty recent calculation.

• 55:49Kelly Weinersmith?

  It's a cool time to be alive.

• 55:51Daniel Whiteson?

  It's a cool time to be alive. But while mercury is amazing and gorgeous and fascinating, please don't play with it. Don't drink it. Don't throw it at your sister.

• 55:59Kelly Weinersmith?

  You probably don't want to put a vial of it on your neck.

• 56:05Daniel Whiteson?

  Though it turned out pretty well for you, Kelly.

• 56:07Kelly Weinersmith?

  That was probably one of the less dangerous things kids like me were doing in the 90s when we were sort of free ranging around our neighborhoods. All right, well, I'm going to get my special Relativity is Awesome t-shirts. Cause you've convinced me and I look forward to talking to you next week.

• 56:23Daniel Whiteson?

  Sounds good. And so for those of you folks out there keeping track, Relativity has now explained two totally different kinds of Mercury, both the orbit of the planet Mercury and the melting point of the element Mercury. Relativity is all over it.

• 56:37Kelly Weinersmith?

  Ah, you know, actually, when I read your intro, I thought to myself, I don't know the story about how Relativity predicted Mercury's orbit. Should that be another episode? Is there a 30 second version or should we do a future episode?

• 56:49Daniel Whiteson?

  Future episode, let's do it.

• 56:51Kelly Weinersmith?

  Future episode, locked in. All right. Thanks for listening. If you want to get in touch, please send us an email at [email protected]. We can't wait to hear from you.

• 57:00Daniel Whiteson?

  Thanks for staying with us for this chemistry episode.

• 57:10Kelly Weinersmith?

  Daniel and Kelly's Extraordinary Universe is produced by iHeartRadio. We would love to hear from you.

• 57:15Daniel Whiteson?

  We really would. We want to know what questions you have about this extraordinary universe.

• 57:21Kelly Weinersmith?

  Want to know your thoughts on recent shows, suggestions for future shows. If you contact us, we will get back to you.

• 57:28Daniel Whiteson?

  We really mean it. We answer every message. Email us at [email protected].

• 57:34Kelly Weinersmith?

  You can find us on social media. We have accounts on X, Instagram, Blue Sky, and on all of those platforms, you can find us at D and K Universe.

• 57:44Daniel Whiteson?

  Don't be shy. Write to us.

• 57:49Speaker 02

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• 57:57Speaker 03

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• 58:21Speaker 01

  That sound? That's the National Squash League. Pro teams, the world's best players, and rally so fast you'll forget to breathe. Season four is in full swing, and every match streams free on YouTube. Big hits, bigger rivalries, and a front row seat from wherever you are. Watch every match for free on YouTube. Search "National Squash League" and hit subscribe or follow live updates on Instagram at NSL.Sport.

• 58:49Speaker 25

  She's been thinking about this sleepover all week, but I think about her food allergies all the time. Fortunately, her doctor prescribed Zolair, omalizumab. It's proven to significantly reduce allergic reactions if a food allergy accident happens.

• 59:02Speaker 26

  Zolair 150mg is a prescription medication used to treat food allergy in people one year of age and older to reduce allergic reactions due to accidental exposure to one or more foods. While taking Zolair, you should continue to avoid all foods to which you are allergic. Don't use if you are allergic to Zolair. Zolair may cause a severe, life-threatening allergic reaction called anaphylaxis. Tell your doctor if you ever had anaphylaxis. Get help right away if you have trouble breathing or if you have swelling of your throat or tongue. Zolair should not be used for the emergency treatment of allergic reactions, including anaphylaxis. Zolair is for maintenance use to reduce allergic reactions, including anaphylaxis, while avoiding food allergens. Serious side effects such as cancer, fever, muscle aches and rash, parasitic infection, or heart and circulation problems have been reported. Please see zolair.com for full prescribing information. Ask an allergist about Zolair. This is an advertisement for Zolair

• 59:47Speaker 26

  paid for by Genentech and Novartis.

• 59:49Speaker 27

  Are you looking for support in your weight management journey? Zepbound terzepatide may be able to help. Zepbound is a prescription medicine used with a reduced-calorie diet and increased physical activity to help adults with obesity or some adults with overweight who also have weight-related medical problems to lose excess body weight and keep the weight off. Zepbound is approved as a 2.5, 5, 7.5, 10, 12.5, or 15-milligram injection. Zepbound contains terzepatide and should not be used with other terzepatide-containing products or any GLP-1 receptor agonist medicines. It is not known if Zepbound is safe and effective for use in children. Don't share needles or... Pens or reuse needles. Don't take if allergic to it.

• 1:00:32Speaker 27

  Or if you or someone in your family had medullary thyroid cancer. Or if you've had multiple endocrine neoplasia syndrome type two. Tell your doctor if you get a lump or swelling in your neck. Stop ZepBound and call your doctor if you have severe stomach pain or a serious allergic reaction. Severe side effects may include inflamed pancreas or gallbladder problems. Tell your doctor if you experience vision changes before scheduled procedures with anesthesia. If you're nursing, pregnant, plan to be, or taking birth control pills. Taking ZepBound with a sulfonilurea or insulin may cause low blood sugar. Side effects include nausea, diarrhea, and vomiting, which can cause dehydration and worsen kidney problems. Talk to your doctor.

• 1:01:11Speaker 27

  Call 1-800-545-5979 or visit zepbound.lily.com. This is an iHeart Podcast. Guaranteed Human.