Pod Insights StarTalk Podcast The Magic of Chemistry with Kate the Chemist About this episode What is chemistry? Neil deGrasse Tyson and comedian Chuck Nice take fan questions on exothermic reactions, PFAS, ice cream, sugar, fire, and more with Kate Biberdorf, aka Kate the Chemist.
Transcript Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.
0:01 Neil deGrasse Tyson? Welcome to StarTalk. Your place in the universe where science and pop culture collide. StarTalk begins right now.
0:14 Neil deGrasse Tyson? This is StarTalk. Neil deGrasse Tyson here, your personal astrophysicist. We've got a Cosmic Queries edition coming. All about chemistry. More on that in just a moment. Chuck.
0:27 Chuck Nice? Hey.
0:27 Neil deGrasse Tyson? How you doing, man?
0:28 Chuck Nice? I'm doing well, man. How you doing?
0:29 Neil deGrasse Tyson? Okay. Who's that sitting next to you?
0:31 Chuck Nice? I gotta tell you, only the most awesome chemist ever.
0:34 Neil deGrasse Tyson? Ever.
0:35 Chuck Nice? Ever.
0:35 Neil deGrasse Tyson? Ever.
0:36 Chuck Nice? If you have anything called social media, then you have seen her conducting demonstrations of chemical reactions and explaining to you the wonderful world of chemistry.
0:49 Neil deGrasse Tyson? Chemistry, Kate the Chemist.
0:50 Kate Biberdorf? Hi.
0:51 Neil deGrasse Tyson? Welcome. Welcome to StarTalk.
0:54 Kate Biberdorf? Thank you.
0:57 Neil deGrasse Tyson? And I have to, I need training on how to pronounce your last name. B-Bieberdorff?
1:03 Kate Biberdorf? B-Bieberdorff, perfect guess. Bieberdorff.
1:05 Chuck Nice? Bieberdorff.
1:06 Kate Biberdorf? So like Justin Bieber and then Dorff, that's what I always say.
1:08 Neil deGrasse Tyson? No, that's, that's wrong.
1:09 Chuck Nice? The alter ego of his fan club.
1:11 Neil deGrasse Tyson? That sounds like a fan club.
1:13 Chuck Nice? I'm a Bieberdorff. I'm a Bieberdorff. Are you a Bieberdorff? I'm a B-Bieber.
1:19 Kate Biberdorf? Oh, I like it.
1:20 Chuck Nice? Yeah, B-Bieber.
1:20 Kate Biberdorf? My, my students call themselves the Bieberdorks, so.
1:23 Neil deGrasse Tyson? Oh, Bieberdorks. Good.
1:24 Kate Biberdorf? Yeah, so I'll take that too. I like it.
1:26 Neil deGrasse Tyson? That's affectionate.
1:27 Kate Biberdorf? Yeah.
1:29 Neil deGrasse Tyson? So you're not just Kate the Chemist in your social media. You are Associate Professor of Instruction and Science Entertainer. That's a thing. I'm glad that's a thing. Why can't that be a thing?
1:40 Chuck Nice? That should be a thing.
1:41 Neil deGrasse Tyson? You know, and Associate Professor of Chemistry, University of Texas, Austin.
1:45 Kate Biberdorf? Yes, hook 'em horns.
1:46 Neil deGrasse Tyson? Hook 'em horns, there it is. Okay. So you built this huge following on social media, blowing shit up. Is this what you do?
1:56 Kate Biberdorf? That's what I do. Yes.
1:58 Neil deGrasse Tyson? That is so cool. So how does that work on Twitter or in the medium where you don't have a video?
2:03 Kate Biberdorf? It's difficult, for sure. I mean, you can share a video on Twitter still. Yeah, but on Twitter, I try to be more academic, right? Highlight articles that I like or science.
2:12 Neil deGrasse Tyson? Twitter X, excuse me.
2:13 Kate Biberdorf? Yes, apologies. Yes, thank you. But you know, highlight good research or hot, hot science in the moment. So it's easy to do that, but I will.
2:19 Neil deGrasse Tyson? Directing people.
2:20 Kate Biberdorf? Correct.
2:20 Neil deGrasse Tyson? Yes.
2:21 Kate Biberdorf? Yes, exactly. Or highlighting scientists that I like and saying, hey, you should follow this person or this person. But you are right. I mean, Instagram and TikTok are my big ones because it's very easy to get somebody to like you, breathe fire. I mean, that's just fun and visually appealing.
2:35 Neil deGrasse Tyson? Yes, yes, yes. And so are these people who would not have otherwise been chemistry fans, do you think, and they're, and they're attracted to your clever way of bringing it down to earth?
2:47 Kate Biberdorf? Well, that's a compliment, so I will take that. But probably, yeah, I mean, honestly, most people hated their chemistry class. I hear that all the time, right? Both of you? Yeah, and that's terrible for me because it's my favorite thing. It's my absolute favorite thing. And so if I can.
3:02 Neil deGrasse Tyson? By the way, anyone in your role who's also trying to do that with math has the same story. People hated their math class.
3:08 Kate Biberdorf? They don't have fire. I at least have fire. I have liquid nitrogen. I have tools in my tool belt that I can use to get kids excited about it.
3:14 Neil deGrasse Tyson? They got nothing.
3:15 Kate Biberdorf? A calculator?
3:18 Kate Biberdorf? It's not as exciting.
3:19 Neil deGrasse Tyson? They can write five to 10 digits. All right. So you have thought about what would excite them?
3:26 Kate Biberdorf? Right.
3:27 Neil deGrasse Tyson? Visually and intellectually.
3:28 Kate Biberdorf? Well, I was raised by psychologists, but all of us agree on William James's theory of emotional memory. And so it's about if you have an emotional response to something, you're more likely to form a memory. So in the classroom, I can use fire. Like if I light my hand on fire, now all of a sudden the students are interested and the research shows I have about 60 seconds to then teach them why that works.
3:47 Neil deGrasse Tyson? We're looking at her hand right now. The research shows that.
3:49 Kate Biberdorf? Yes.
3:50 Neil deGrasse Tyson? Rather than your life experience.
3:51 Kate Biberdorf? Yeah, also true, yes.
3:53 Neil deGrasse Tyson? That would also count as data, for sure.
3:55 Kate Biberdorf? For sure. Oh, for sure.
3:56 Neil deGrasse Tyson? So you're burning it like an alcohol or something in your hand?
3:58 Kate Biberdorf? You dunk your hand in water first and so you cover it. Water has a really high specific heat capacity and so it takes a lot of energy to raise the temperature. Sure of the water.
4:06 Neil deGrasse Tyson? So it acts like a Insulating layer.
4:07 Kate Biberdorf? Exactly. Yes, exactly. So it acts like a lab coat. Then you grab bubbles that have been pumped full of methane. Methane methane is very flammable. You hold on to it, you can light the the bubbles on fire and your hand doesn't burn at all. As long as you keep your fingers open. If you close your fingers or you're wearing rings, now you have a problem. But it's totally fine. But now the students are interested.
4:25 Neil deGrasse Tyson? But just to be clear, methane, such as the gas that comes out of
4:29 Kate Biberdorf? Cows. That's what you were just saying?
4:32 Neil deGrasse Tyson? Okay, cows.
4:34 Chuck Nice? Let's leave it at cows.
4:34 Neil deGrasse Tyson? Let's leave it at cows.
4:35 Chuck Nice? We'll leave it at cows.
4:36 Neil deGrasse Tyson? It's a flammable gas.
4:37 Chuck Nice? Right.
4:38 Neil deGrasse Tyson? So what you've done, at the risk of stating the obvious, is you've taken psychological research to turn yourself into a better chemistry teacher.
4:45 Kate Biberdorf? Yes, 100%. 100%. Yeah, I mean, the point, at the end of the day, my goal is for students to become good scientists. Um, I only 5% of those students become chemistry majors. So I really want them to be educated voters. I want them to be able to
5:00 Neil deGrasse Tyson? In your class?
5:01 Kate Biberdorf? In my class, yeah, my class. And so I want them to be educated voters. I want them to have quantitative reasoning skills, quantitative thinking skills. And so for me, it's all about building those skills through the lens of chemistry to try to make my students a smart, like, the best citizens we possibly can have.
5:16 Neil deGrasse Tyson? And how about your following? They just want to see stuff blow up?
5:18 Kate Biberdorf? More, yes.
5:19 Neil deGrasse Tyson? Or they could become like chemical engineers.
5:21 Kate Biberdorf? Yes, that's for sure.
5:22 Neil deGrasse Tyson? You must know, because they'll write to you.
5:23 Kate Biberdorf? Yes, they do.
5:24 Neil deGrasse Tyson? Yeah, so what do you know?
5:25 Kate Biberdorf? They like the explosions. They like the really quick, fast things. They do not want me to drone on about the structure of an atom.
5:30 Chuck Nice? But you never know when that will spark the curiosity that leads them to want to know what's behind that explosion.
5:39 Neil deGrasse Tyson? Yeah, yeah, there it is.
5:40 Chuck Nice? My son started off with just chemistry and liked it so much that he's going to school now for biochem.
5:47 Kate Biberdorf? Amazing.
5:48 Chuck Nice? Yeah, he's gonna be a biochemist. That's what he tells me he wants to be.
5:51 Neil deGrasse Tyson? You can tell me that.
5:52 Chuck Nice? And I told him, don't be a biochemist, own a biochem company.
6:00 Kate Biberdorf? Not a bad idea.
6:02 Neil deGrasse Tyson? Let's get some basic chemistry on the table, okay? I can't claim to even know the answer to this myself. What is a chemical reaction?
6:12 Kate Biberdorf? Oh, okay. So chemistry in general is the study of energy and matter and how they interact with each other. And so a chemical reaction is when you have a starting material, you do something to it and you get a brand new product. So like if you're baking a cake, your reactants would be eggs, flour, sugar, chocolate chips, something like that, and then you add heat, right?
6:34 Neil deGrasse Tyson? You put chocolate chips in cake?
6:35 Kate Biberdorf? I don't know, I'm just making something up. Well, maybe you melt it, so it's a chocolate cake.
6:39 Neil deGrasse Tyson? Okay, good.
6:40 Kate Biberdorf? There we go, okay.
6:41 Neil deGrasse Tyson? A molten chocolate cake, okay? That's good, that's good.
6:43 Kate Biberdorf? Okay, yeah, okay, so then we have to heat it up, right? So you're gonna put it in the oven.
6:47 Neil deGrasse Tyson? So it's an energy source.
6:48 Kate Biberdorf? An energy source.
6:49 Neil deGrasse Tyson? Going into the cake.
6:49 Kate Biberdorf? Exactly, and then you're going to take it out and you have a brand new product. So a chemical reaction is you have starting materials, which we call reactants, and then you have a product at the end, which is the goal. That's what you're trying to produce, what you're trying to make, or what you're trying to study.
7:02 Neil deGrasse Tyson? Okay, so now, there are many things you can do that with, but then if you just wait long enough, this thing that you made turns into something else. Mm-hmm. Like... Like iron turning into rust.
7:14 Kate Biberdorf? Yes.
7:15 Neil deGrasse Tyson? Other things can happen, even after you're done doing what you're doing.
7:19 Kate Biberdorf? Oh, yeah.
7:19 Neil deGrasse Tyson? So they would happen without your intervention.
7:22 Kate Biberdorf? Correct, so that goes back to being a spontaneous reaction. And so I'm gonna jump into some thermodynamics. Hold me back if I go too far here. Okay, okay.
7:31 Neil deGrasse Tyson? Plus, I'm hearing these terms, it's easy to see now why people use the chemistry term to refer to human relationships. Right. We have spontaneous reaction. Right. Chemical, who's in our chemistry.
7:41 Kate Biberdorf? Yes.
7:41 Neil deGrasse Tyson? Use your words, not my words.
7:42 Kate Biberdorf? They are my words.
7:43 Neil deGrasse Tyson? Right, right, Astro, we don't have that. You got all the words for relationships.
7:47 Kate Biberdorf? Very fair. So for a spontaneous reaction, this is a chemical reaction that will happen on its own in isolation. And so usually that's something that's exothermic, so it's gonna give off heat as it goes from the reactants to the products, and it's usually something that has an increase in entropy. And so we know the second law of thermodynamics is to increase the entropy of the universe. And so if we have something that's exothermic, meaning it gives off heat, and then it has an increase in entropy, meaning the energy is spread out more so, that's a favorable reaction, that would be spontaneous.
8:19 Neil deGrasse Tyson? That's just the universe, just be in the universe.
8:21 Kate Biberdorf? Exactly.
8:21 Neil deGrasse Tyson? Without your intervention.
8:22 Kate Biberdorf? Without my intervention. So that's a reaction that will happen on its own. So they don't even need me to do this.
8:27 Neil deGrasse Tyson? Okay, so does the formation of diamonds count as happening on its own if that needs pressure and temperature and time?
8:35 Kate Biberdorf? That's what I was gonna say. What are your conditions? So I would say yes, over time.
8:39 Neil deGrasse Tyson? I just can't put a lump of carbon on my table and wait for it to become a diamond.
8:43 Kate Biberdorf? Not for us. We will never see that. No.
8:45 Chuck Nice? But even though I did get a lump of carbon every year for Christmas, but that's okay. I mean, we're not gonna get into that right now.
8:52 Kate Biberdorf? Sorry.
8:53 Chuck Nice? However, but I mean, is it really happening on its own, or is the Earth actually providing the conditions necessary to make that reaction happen?
9:01 Kate Biberdorf? Great point. Absolutely great point. So on Earth, we refer to something as SATP or STP, so standard temperature and pressure. If we're talking about thermodynamics, that would mean we're at 25 degrees Celsius, so 298 Kelvin, and then one atmosphere. And so those are the conditions where it would happen on its own naturally.
9:17 Neil deGrasse Tyson? 25 degrees Celsius. That's like a little higher than room temperature?
9:22 Kate Biberdorf? Yeah, 25 is what we call room temperature.
9:24 Neil deGrasse Tyson? Oh, I didn't know that.
9:25 Kate Biberdorf? Yeah, 25, in chemistry at least, that's how we define that. And so that's probably like, I don't know, 73, 75, something like that?
9:30 Neil deGrasse Tyson? Yeah, it's a little above 72.
9:31 Kate Biberdorf? Oh, 72, okay. 73, that's what I said. Okay, cool.
9:34 Neil deGrasse Tyson? Yeah, yeah, yeah.
9:34 Chuck Nice? Okay, and then at one atmosphere?
9:36 Kate Biberdorf? At one atmosphere.
9:37 Neil deGrasse Tyson? Of pressure.
9:38 Kate Biberdorf? Of pressure, right. And so that's how our chemical reactions occur here on Earth, because those are what our standard conditions are.
9:44 Neil deGrasse Tyson? So I heard something. Was it, is it beryllium? One of these elements on the periodic table in American charts is listed as a liquid.
9:59 Neil deGrasse Tyson? But in the UK, it's listed as a solid.
10:02 Kate Biberdorf? But that's gallium.
10:03 Neil deGrasse Tyson? Gallium.
10:04 Kate Biberdorf? Gallium. I was like beryllium.
10:07 Kate Biberdorf? It's okay. Sorry.
10:10 Neil deGrasse Tyson? Your voice was stupid.
10:12 Kate Biberdorf? No.
10:13 Neil deGrasse Tyson? So, so we talk about gallium.
10:15 Kate Biberdorf? Gallium.
10:16 Neil deGrasse Tyson? Gallium. So in the UK, it's listed as a solid because the room temperature in the UK is colder than here.
10:24 Chuck Nice? Wow.
10:25 Neil deGrasse Tyson? And so, and it, and it changes state at that point. So the conditions are everything. What you think something is, is only what it is under those conditions. Under those conditions.
10:34 Kate Biberdorf? Exactly. Yes.
10:36 Neil deGrasse Tyson? Very cool. So one last thing about these exothermic reactions. There's also endothermic, if I remember correctly. So that's exactly what's going on. If you have a sore muscle, you get this pack and you sort of smash it and it becomes warm. There's another pack you can buy, you smash it.
10:51 Chuck Nice? It becomes cold.
10:52 Neil deGrasse Tyson? It becomes cold.
10:53 Kate Biberdorf? Mm-hmm.
10:53 Neil deGrasse Tyson? So people like you have something to do with that.
10:56 Kate Biberdorf? Oh, thank you. Yes, I'll take credit for that. Absolutely.
10:59 Neil deGrasse Tyson? Yeah, your people.
11:00 Kate Biberdorf? My people.
11:01 Neil deGrasse Tyson? Your people. So you have special chemicals in there, which when combined, forcibly combined, will either absorb energy or emit energy or release energy. And so you have to know what those are in advance, obviously.
11:14 Kate Biberdorf? Oh, yeah, absolutely. And so usually how those things work is there are, there's one pouch that's filled with something and then there's another pouch on the inside. And so you're breaking the two pouches and allowing for the two things to mix.
11:24 Neil deGrasse Tyson? The membrane between them.
11:25 Kate Biberdorf? Right, exactly. It's a really thin membrane and just with a little bit of force, we can break it.
11:29 Neil deGrasse Tyson? Okay.
11:29 Kate Biberdorf? What's neat for endothermic reactions is it's usually a salt. A salt that will dissolve in water, that's going to drop the temperature down. It's freezing point depression. And so that's what's going to be very, very cold and we'll use it if you have an injury.
11:40 Chuck Nice? Right.
11:41 Neil deGrasse Tyson? Okay.
11:41 Chuck Nice? And that's what they do when you make ice cream. That's why they use salt.
11:44 Kate Biberdorf? Yes. Oh, yeah, that's correct.
11:45 Neil deGrasse Tyson? Well, I, I think there's a different reason.
11:47 Chuck Nice? Really?
11:48 Neil deGrasse Tyson? Yeah.
11:48 Chuck Nice? Why?
11:50 Kate Biberdorf? If you make it by your hands, though, you add a little bit of salt for it so that you can go back and forth, yeah?
11:55 Neil deGrasse Tyson? Make ice cream in your hands?
11:56 Kate Biberdorf? Well, you put it in a Ziploc bag and then you put milk and sugar and vanilla.
12:01 Chuck Nice? Oh, you can put it in a towel and you put that inside of another bag of ice and salt. And then take the towel and just whip it around.
12:09 Neil deGrasse Tyson? I'm an ice cream guy.
12:10 Chuck Nice? Okay.
12:11 Neil deGrasse Tyson? From way back.
12:12 Chuck Nice? All right.
12:13 Neil deGrasse Tyson? I should weigh 100 pounds more, but I exercise just to wear off the ice cream.
12:17 Chuck Nice? Just so I can eat ice cream.
12:18 Neil deGrasse Tyson? Got your bucket and it's filled with ice.
12:20 Chuck Nice? Right.
12:20 Neil deGrasse Tyson? If you try to make ice cream that way, the cold of the ice. Is only pulling the heat out of the ice cream at the points where the solids are touching the rotating cylinder. Everywhere else is air. Alright. You put salt on the ice. The ice melts at that temperature.
12:44 Chuck Nice? Right.
12:44 Neil deGrasse Tyson? So now the medium is liquid.
12:46 Chuck Nice? Liquid, and the liquid is now touching every single part of the cylinder.
12:49 Neil deGrasse Tyson? And it is way better. At the same temperature as the ice, correct.
12:53 Chuck Nice? That makes sense.
12:53 Neil deGrasse Tyson? It's way better at sucking the heat out than just solids that it's turning within.
12:59 Chuck Nice? Alright, I'll accept that. Cogent argument you have made.
13:02 Neil deGrasse Tyson? That's all I'm saying.
13:03 Chuck Nice? Which I should have known, because at first I was just like, alright, I finally got this guy.
13:08 Chuck Nice? I'm like, I know for a fact that it's to lower the temperature, but that makes perfect sense.
13:12 Neil deGrasse Tyson? Yeah, yeah.
13:12 Chuck Nice? Makes perfect sense.
13:13 Neil deGrasse Tyson? So I would claim that salt in water does not lower the temperature. That's what I'm claiming.
13:17 Kate Biberdorf? Salt in water will always have freezing point depression. That is a thing, we can measure that.
13:21 Neil deGrasse Tyson? I get that.
13:22 Kate Biberdorf? Yeah.
13:22 Neil deGrasse Tyson? But if water's at a given temperature
13:25 Kate Biberdorf? Mm-hmm.
13:25 Neil deGrasse Tyson? and salt is just the salt, I'm gonna assert that you put the salt in the water, nothing happens to the temperature. That's what I'm gonna claim.
13:33 Kate Biberdorf? False. Freezing point depression, it will go down. Delta T is equal to negative I K F times the molality.
13:41 Chuck Nice? Mic drop!
13:43 Kate Biberdorf? Um, if you put salt in water, it goes down by negative 1.86 degrees Celsius.
13:48 Neil deGrasse Tyson? For?
13:49 Kate Biberdorf? It's molality, so it would be moles of solute divided by kilograms of solvent.
13:54 Neil deGrasse Tyson? And does it matter what kind of salt?
13:55 Kate Biberdorf? Definitely. Yeah, it has to do with the Van Hooft factor.
13:58 Neil deGrasse Tyson? Okay, okay.
13:58 Kate Biberdorf? Yeah, oh yeah.
13:59 Neil deGrasse Tyson? But at home, you just have table salt.
14:00 Kate Biberdorf? Correct, and so it has a Van Hooft factor of two.
14:02 Neil deGrasse Tyson? So, will this work for table salt?
14:04 Kate Biberdorf? Absolutely, yes. Because when you put sodium chloride in water, it's gonna break apart into the ions.
14:09 Neil deGrasse Tyson? I'm doing the experiment tonight.
14:10 Kate Biberdorf? Do it, you will feel it. You will feel it in your hand.
14:12 Neil deGrasse Tyson? I'm doing the experiment.
14:13 Chuck Nice? That is cool, man. I'm, I love it. The experiment gauntlet has been thrown down!
14:18 Kate Biberdorf? I, I promise you.
14:20 Neil deGrasse Tyson? Okay, so how many degrees?
14:22 Chuck Nice? I challenge you, sir. Ions at dawn.
14:24 Kate Biberdorf? Two Celsius, max.
14:25 Neil deGrasse Tyson? Two Celsius.
14:26 Kate Biberdorf? Max.
14:26 Neil deGrasse Tyson? Of what volume of, of salt?
14:29 Kate Biberdorf? I would make a super saturated solution.
14:31 Neil deGrasse Tyson? Ooh.
14:31 Kate Biberdorf? Yeah. So take a bunch of water, just dump salt in until you can see it at the bottom.
14:34 Neil deGrasse Tyson? Yeah.
14:35 Kate Biberdorf? Stir, stir, stir, stir, stir. And you'll, you'll feel it. You will physically feel the temperature go down.
14:39 Neil deGrasse Tyson? So, I got a super saturated. A lot of salt.
14:42 Kate Biberdorf? Just, yeah, but don't do a lot of water. Just do a cup of water.
14:47 Kate Biberdorf? Like, you'll feel it.
14:59 Speaker 03 Hello, I'm Alexander Harvey and I support StarTalk on Patreon. This is StarTalk with Dr. Neil deGrasse Tyson.
15:16 Neil deGrasse Tyson? Well, you have a huge fanbase and they heard you were coming on the show and we solicited inquiries from them.
15:22 Kate Biberdorf? Exciting.
15:23 Neil deGrasse Tyson? And what do you got here? I haven't seen them, have you seen them?
15:26 Chuck Nice? No, we don't let them.
15:28 Neil deGrasse Tyson? Oh, yeah, okay. It's a loving.
15:31 Chuck Nice? Yeah, they only ask things that they're really a great audience and they're very curious and they ask.
15:37 Neil deGrasse Tyson? And they pay for the privilege to ask a question.
15:39 Chuck Nice? Yes, they are Patreon members and so.
15:41 Neil deGrasse Tyson? No, just per month.
15:43 Chuck Nice? It's $5 a month if you're interested out there and you want to join Patreon.
15:46 Neil deGrasse Tyson? Which is the cheapest membership of anything you would ever have.
15:48 Chuck Nice? All right, here we go. This is Samuel Barnett. He says, greetings from London, England. Given the properties of molecules don't seem to match the properties of the elements they're made of. Example, water extinguishing fire despite being made of highly flammable oxygen plus hydrogen, which we learned that's the big tanks on the rockets that take the space shuttle to space.
16:11 Neil deGrasse Tyson? Yeah, the orange tank right there.
16:12 Chuck Nice? The orange tank, there it is. So, he says, is there a way to tell how a new molecule will behave ahead of time? Or is it just a case of suck it and see? Or I'll.
16:24 Neil deGrasse Tyson? I'd love that.
16:25 Chuck Nice? I'll say, I'll clean it up for him. Trial and error.
16:28 Neil deGrasse Tyson? Can you predict? Two new elements, when they come together and they make something new, can you predict its properties?
16:36 Chuck Nice? Yeah.
16:36 Kate Biberdorf? We will try to. So, the periodic table is organized based on size, but it's also based on chemical properties.
16:44 Neil deGrasse Tyson? Size meaning size of the nucleus.
16:45 Kate Biberdorf? Uh, size of the whole atom.
16:47 Neil deGrasse Tyson? The whole atom.
16:48 Kate Biberdorf? The whole atom, yeah, so including the electrons. And so, when you look at a periodic table, if you go down a column, you would expect for every species in that column to behave similarly. So, for example, if you go all the way to the far right on the periodic table, those are your inert gases, your noble gases, all of them have full octet shells, meaning they're not looking for an external valence electron, they're full.
17:08 Neil deGrasse Tyson? They're happy in and of themselves.
17:10 Kate Biberdorf? They're satisfied.
17:10 Neil deGrasse Tyson? There's gotta be some psychological.
17:12 Chuck Nice? Yes, exactly. You're content. I really like it here. I gotta tell you, this electron shell just suits me perfectly.
17:20 Neil deGrasse Tyson? I know, I don't need anybody else to help.
17:22 Chuck Nice? You know, I'm looking down at my nucleus, I'm just as happy as I can be.
17:25 Neil deGrasse Tyson? That's, there it is. The right hand call personified by Chuck.
17:30 Kate Biberdorf? Yes, but you would expect everything, so like argon, neon, krypton, all those gases to behave in a similar way. And so let's say you look at group five, you've got nitrogen at the top, phosphorus is right underneath it. So you would expect for nitrogen and phosphorus to behave similarly, and that makes sense.
17:46 Neil deGrasse Tyson? In a reaction, in a chemical reaction.
17:47 Kate Biberdorf? In a reaction if it's bonded to the same partners. So I would compare NH3 with pH3, and I would expect them to behave similarly, not the exact same way.
17:55 Neil deGrasse Tyson? NH3, so that would be ammonia.
17:57 Kate Biberdorf? Ammonia versus pH3 phosphine. And so we could compare the two of those and expect them to behave similarly. They each have a lone pair, they've got an electron pair available.
18:06 Neil deGrasse Tyson? Interesting, that's a fair answer, I like that.
18:07 Kate Biberdorf? Oh, totally.
18:08 Neil deGrasse Tyson? Yeah, yeah.
18:09 Kate Biberdorf? You can predict it, but then you test it.
18:11 Chuck Nice? Right, you predict it and then you, then you blow something up.
18:15 Neil deGrasse Tyson? Yeah, but I bet people before you understood the periodic table, there must have been a lot of trial and error.
18:20 Kate Biberdorf? Of course, there still is, there's still trial and error. You have a guess, you want to use your money the best you possibly can, you only have a limited funding, so you want to put your eggs in the best basket.
18:30 Chuck Nice? So how about, now, there's something in AI, I believe it's called offline reinforcement learning. So what that does is the AI observes a bunch of things similar, and then it makes predictions based on what it's observed. Do you guys use anything like that to figure out?
18:48 Kate Biberdorf? That's the definition of science, that's what we do.
18:50 Neil deGrasse Tyson? Duh.
18:51 Kate Biberdorf? Right, I mean, right? We watch something, we try to detect patterns, that's all we learn in grad school.
18:57 Neil deGrasse Tyson? We use AI, we use NI, natural intelligence.
18:59 Chuck Nice? Oh, okay, right on.
19:02 Neil deGrasse Tyson? This is my, I'm gonna say, that's a little more rare.
19:08 Neil deGrasse Tyson? All right, next question.
19:09 Chuck Nice? We don't find that very...
19:09 Neil deGrasse Tyson? Who do you have?
19:10 Chuck Nice? All right, this is Mike Mohammed Kaki. He says, greetings, Dr. Tyson, Dr. Bieberdorf, and Lord Nice. Mike Kaki here from Berlin, Germany. Can you explain the role of activation energy in a chemical reaction and how it influences the rate of reaction?
19:26 Neil deGrasse Tyson? I love that.
19:26 Kate Biberdorf? That's a beautiful question.
19:27 Neil deGrasse Tyson? What is activation energy?
19:28 Kate Biberdorf? So, activation energy is the minimum energy required for a chemical reaction to occur.
19:34 Neil deGrasse Tyson? So it's sitting there, otherwise happy.
19:36 Kate Biberdorf? Yeah.
19:36 Neil deGrasse Tyson? Until you put energy in it, then it runs away?
19:39 Kate Biberdorf? Yeah, sometimes, yes, sometimes no. It kind of depends on the conditions and what else is going on in the environment. But in general, if you're going to rearrange atoms, likely you're going to need to break bonds and then make bonds. And so, activation energy is that minimum energy required to actually rearrange those atoms.
19:55 Neil deGrasse Tyson? In whatever way is your intent.
19:57 Kate Biberdorf? Right, exactly. And so, it's based on the collision. And so, the orientation of the molecules matters. If you need them to hit head-on, and then they do like side by side, you might not have the collision.
20:06 Neil deGrasse Tyson? Wait a minute, you know how the molecules are oriented?
20:10 Kate Biberdorf? Well, we know that what orientation or what collisions are favorable. And so, we know if these two atoms need to interact and form a bond, if you have the molecules slap each other from the other side...
20:20 Chuck Nice? So, do molecules have like docking ports, basically?
20:25 Kate Biberdorf? I'm OK with that.
20:26 Neil deGrasse Tyson? Yeah, but what I'm saying... Yes, but how do you configure them to know which docking ports are pointing which way? Aren't they littler than you can see?
20:35 Kate Biberdorf? Well, sure, but you know that if you have one side of the molecule, like, let's say I'm a molecule, and I know that my right hand needs to form a bond with your right hand. If our left hands collide, we're not going to form a bond, because those aren't favorable interactions.
20:48 Neil deGrasse Tyson? But how do you control that?
20:50 Kate Biberdorf? We can't.
20:51 Neil deGrasse Tyson? Oh, OK.
20:51 Kate Biberdorf? No.
20:52 Neil deGrasse Tyson? That's what spooked me.
20:53 Kate Biberdorf? Oh, no.
20:53 Neil deGrasse Tyson? I thought she's up to with tweezers, you know, putting one molecule...
20:57 Kate Biberdorf? That's the dream, I would love that.
20:58 Neil deGrasse Tyson? To another, all right.
20:59 Kate Biberdorf? No, no, no, we can't, because it's usually in solution or in gas phase. So the collisions are not... Yeah, we can't control that.
21:04 Neil deGrasse Tyson? OK.
21:04 Kate Biberdorf? No, but what has to happen is they have to collide with enough velocity, so kinetic energy, to overcome the potential energy push away. So the proton-proton...
21:13 Neil deGrasse Tyson? That would count as activation energy, the speed if they collide.
21:15 Kate Biberdorf? Part of it, it's part of it.
21:17 Neil deGrasse Tyson? Okay.
21:17 Kate Biberdorf? All of it. And so you have to have the energy coming in that is stronger than the proton-proton repulsions that are happening between the atoms. And it has to be the right collision. All of that is kind of looped up into activation energy.
21:28 Neil deGrasse Tyson? And can you know that in advance, like from equations? Or do you, will you measure that?
21:33 Kate Biberdorf? A hundred percent, yeah. So you would use an Arrhenius law. So it's the natural log of rate one over rate two is equal to your activation energy divided by R times one over T1 minus one over T2. Arhenius.
21:44 Chuck Nice? Wow, you are good at this.
21:46 Kate Biberdorf? I had to find it.
21:47 Neil deGrasse Tyson? This is like way back.
21:48 Kate Biberdorf? Way back, yeah.
21:49 Neil deGrasse Tyson? Arhenius?
21:49 Kate Biberdorf? Yeah.
21:50 Neil deGrasse Tyson? When was Arhenius?
21:51 Kate Biberdorf? Ooh, I don't know, I couldn't give you a year.
21:53 Chuck Nice? Long, long enough ago that nobody is named Arhenius. That's how long ago it was. You have never met an Arhenius in your life.
22:02 Neil deGrasse Tyson? And Arhenius doesn't even have a middle or last name.
22:05 Chuck Nice? It's like Cher, I'm Arhenius.
22:09 Kate Biberdorf? I love that.
22:10 Neil deGrasse Tyson? Yeah.
22:10 Chuck Nice? Yeah. You know what I'm trying to figure out though, then? Some reactions are just so favorable or so common. Can you take what you said and I'm lighting a piece of paper on fire? Which is a reaction that everybody knows. What would be happening there from what you just explained?
22:25 Neil deGrasse Tyson? I would say the activation energy was the match.
22:29 Neil deGrasse Tyson? I'm spitballing here.
22:30 Kate Biberdorf? Part of it.
22:31 Neil deGrasse Tyson? But I'm thinking, I'm just saying, I'm just saying.
22:33 Kate Biberdorf? So if you have a fire, that's a combustion reaction. So you have a source of fuel, you treat it with oxygen, and you produce carbon dioxide and water. And so what you're doing is breaking all of the bonds in the fuel and the oxygen, and you're rearranging it to form carbon dioxide, CO2, and then H2O. And so it's all about literally pulling these species apart, pulling the atoms apart, and then allowing them to rearrange and form a new bond.
22:55 Neil deGrasse Tyson? And is it, based on what we said moments ago, is it fair to say that whatever is the configuration of the molecules in the paper, the configuration afterwards has lower energy? Because that, all that energy became a fire.
23:10 Chuck Nice? Well, you release the energy.
23:10 Neil deGrasse Tyson? Right. Is that a fire? Did I say that right?
23:12 Kate Biberdorf? If it's favorable, yes. If it's favorable, you're going from higher energy to lower energy.
23:17 Neil deGrasse Tyson? Yes.
23:17 Kate Biberdorf? But if we had to force that, if we were in like extreme conditions to make this happen, then not necessarily. You can force things to go higher energy. But usually, for what you're saying.
23:25 Neil deGrasse Tyson? At the cost of putting the energy in.
23:26 Kate Biberdorf? Correct. Yes, yes.
23:27 Chuck Nice? Okay.
23:28 Kate Biberdorf? Exactly.
23:28 Chuck Nice? All right. That was cool, man. Thanks a lot.
23:30 Kate Biberdorf? Can I do one clarification, though?
23:31 Neil deGrasse Tyson? Yeah.
23:32 Kate Biberdorf? Okay, so, activation energy is about kinetics. Kinetics is the study of time. Thermodynamics is the study of energy. And so when we're talking about exo and endothermic, that's talking about the energy transitions. You're going from high energy to low energy, exo. Low energy to high energy, endo. That's thermodynamics. And so that's, will it happen? Is it possible for this reaction to occur? Kinetics is how long. And so activation energy is really a measurement of how long something's gonna take. So you would need enough energy and it can, it can guide us to figure out rate constants. And so often, people combine these two things, but it's, will it happen is thermo.
24:05 Neil deGrasse Tyson? At all.
24:05 Kate Biberdorf? At all. And then, how long? And so from a standpoint of like going into lab, I care about kinetics. I wanna know how long my reaction's gonna take.
24:12 Neil deGrasse Tyson? Yeah.
24:12 Kate Biberdorf? Cause can I go home? Do I have to stay here all night? Like, so kinetics actually measures. So that's why people care about activation energy.
24:18 Neil deGrasse Tyson? So you want the experiment to be done before you go to sleep?
24:20 Kate Biberdorf? Yes. Or, or like...
24:21 Neil deGrasse Tyson? Or before you die.
24:22 Kate Biberdorf? Right, or you can set it up and then go home and work it up in the morning. That's the best case scenario.
24:26 Chuck Nice? Okay. All right, this is Lawrence Harris. And Lawrence says, "Good day, gentlemen and gentle lady. What is happening when you raise sugars to the candy temperature? It starts as a liquid, becomes a soft candy, but if you keep raising the temperature, it will eventually become hard."
24:46 Neil deGrasse Tyson? What's up with that?
24:47 Chuck Nice? What is going on there? And by the way, worst candy ever.
24:52 Neil deGrasse Tyson? Mm-hmm. And also, there it is, a liquid, and you think, oh, let me just taste that. It's like, whoa! That's way hotter than boiling water.
24:59 Chuck Nice? Look at that, I burned not only my finger, I don't have a finger, I have no tongue. I hate candy now. This is just a disaster.
25:05 Neil deGrasse Tyson? I hate chemistry.
25:06 Chuck Nice? This is terrible.
25:08 Kate Biberdorf? So we talked earlier about dissolving salt in water.
25:11 Neil deGrasse Tyson? Yes.
25:11 Kate Biberdorf? And it's a very similar thing. So you're gonna dissolve sugar in water, they're gonna form intermolecular forces, and so that's gonna dissolve the sugar crystals with the water molecules.
25:19 Neil deGrasse Tyson? Will that also drop the temperature?
25:20 Kate Biberdorf? In the beginning, yes, but it's not gonna be as much because it has a van- Haag factor of one. It doesn't break apart.
25:25 Neil deGrasse Tyson? That's somebody else.
25:26 Kate Biberdorf? Yes, that's somebody else.
25:27 Neil deGrasse Tyson? Some other chemist of the past.
25:29 Kate Biberdorf? And so, for the ionic species, when you put them in water, they break apart.
25:32 Neil deGrasse Tyson? I want a Beibdorff factor.
25:33 Kate Biberdorf? You want... Nice, nice. I don't have one.
25:37 Neil deGrasse Tyson? You don't have a factor?
25:38 Kate Biberdorf? No.
25:38 Neil deGrasse Tyson? You can't hang unless you have a factor.
25:39 Kate Biberdorf? I know. Alright, well, next time, I'll have one by the time we come back. But for sugar, you're gonna dissolve, in theory, it would decrease your freezing point, but it's not gonna be much, because it's a covalent species. In the same breath, when you put sugar in water, it's going to increase your boiling point. And so that's why you can get that temperature a little bit hotter, because the sugar is there to kinda mess with that. So, what's interesting about sugar is that when you heat it up, it's gonna dissolve, you're going to increase the solubility, and so that's...
26:07 Neil deGrasse Tyson? That's true for anything.
26:08 Kate Biberdorf? For anything, yeah. Well, it's true for salts and solids, solutes. But if you use a gaseous solute, you increase the temperature, it decreases. Yeah, it's the other way.
26:16 Neil deGrasse Tyson? So if you boiled soda, then the gas just comes out, it doesn't stay dissolved in.
26:21 Kate Biberdorf? Boom.
26:21 Neil deGrasse Tyson? Right, got it. It's the opposite.
26:22 Kate Biberdorf? The opposite, exactly. So when you add sugar in, you're gonna heat it up, and then it's gonna dissolve, and so that's why you heat it. But it's the cooling process that really dictates whether or not you're gonna have like a smooth candy or the hard candy, like rock candy. So if you don't touch it at all, you're gonna allow for your system to kinda minimize the entropy, lock into these beautiful cages.
26:40 Neil deGrasse Tyson? Give it a chance to do it all by itself.
26:42 Kate Biberdorf? Exactly, yes. Let it settle, and then you'll get these gorgeous rocks on, and you probably have to put like a stick in there, but you'll get those rock candies that are typical of rock candy. But if you mess with it while it's cooling down, if you stir it, if you kinda shake it up a little bit, you can't form those gorgeous crystals, and so you're not gonna get rock candy, you're gonna get something closer to like fudge, and so it's a lot smoother. And so it's really, in my opinion, all the cooling process. And like, how are you allowing those crystals to form?
27:05 Neil deGrasse Tyson? It's not how you heat it, it's how you cool it.
27:06 Kate Biberdorf? That's my understanding.
27:08 Chuck Nice? No, that makes sense. My mom used to make candied sweet potatoes.
27:12 Kate Biberdorf? Oh.
27:13 Chuck Nice? And the way you start the candy process is, and they call it candy, it wasn't actual candy, it's a sweet potato with a sugar coating. But the way you start it is you just take regular table sugar, you put it in a pan, and under a low but intense enough to melt heat, you bring the sugar slowly up to a temperature where...
27:34 Neil deGrasse Tyson? Just pure sugar.
27:35 Chuck Nice? Just pure sugar.
27:35 Neil deGrasse Tyson? No water, anything.
27:36 Chuck Nice? And no water, but you can't do it too fast, because you'll just burn the sugar.
27:40 Neil deGrasse Tyson? Burn the sugar.
27:41 Chuck Nice? But what happens is, the sugar, very slowly, as you... Watch it, you can see it from the bottom as wherever the contact with the pan is. It just kind of splays out and becomes brown and caramel like. And it slowly becomes this kind of gooey like caramel like sugar. And then depending on how you cool it or you do something to it, you stir it, whatever. But then it becomes like, like a syrupy fudge. And then when it cools, it just becomes like a little like, like caramel coating over top of the sweet potato.
28:14 Neil deGrasse Tyson? So your kitchen was a chemistry lab?
28:15 Chuck Nice? Oh, definitely. Let me tell you something. It was one of my favorite things to watch.
28:19 Neil deGrasse Tyson? So kitchens are the thing.
28:21 Kate Biberdorf? Yes, every kitchen is a chemistry lab. Thank you for making my point.
28:25 Neil deGrasse Tyson? Yes, because that's, it's just, I need some of this and some of that.
28:29 Kate Biberdorf? Yes.
28:30 Neil deGrasse Tyson? Lined up for you in all the cabinets.
28:31 Chuck Nice? Yeah, you know, I didn't think of it until now, but that's absolutely.
28:34 Kate Biberdorf? Especially baking. Baking for sure is chemistry. Cooking is also, but there's a time component. You can have fun with it. Baking is precise. You need to be exact. Yeah.
28:43 Neil deGrasse Tyson? But if you take albumin from an egg, which is otherwise transparent, then you heat it. Not many things will you heat till they then become solid, but the color of this part of it becomes solid.
28:55 Kate Biberdorf? Yeah.
28:55 Neil deGrasse Tyson? That's kind of weird.
28:56 Kate Biberdorf? Well, it's all about those proteins, right? I think they're opening up and then they can form bonds between each other.
29:01 Chuck Nice? Right.
29:01 Neil deGrasse Tyson? So I've seen this done and I thought it was magic where if you take sweetened condensed milk. Okay, and you boil the can closed for like an hour. Then pressure builds up in the can and then you come back and then you open it and it's like caramel pours out.
29:20 Chuck Nice? Wow.
29:21 Neil deGrasse Tyson? Okay. You haven't done that?
29:22 Kate Biberdorf? I have not done that.
29:23 Neil deGrasse Tyson? Oh my gosh!
29:24 Kate Biberdorf? I'll try that.
29:25 Neil deGrasse Tyson? I thought of the experiment, the chemist hasn't done yet.
29:29 Kate Biberdorf? No.
29:30 Neil deGrasse Tyson? So sweetened condensed milk.
29:31 Kate Biberdorf? Okay.
29:32 Neil deGrasse Tyson? Okay.
29:32 Kate Biberdorf? So it must have a really high sugar content, right? And it's condensed.
29:37 Neil deGrasse Tyson? Yeah, use it for things like key lime pies.
29:39 Chuck Nice? All kinds of baking.
29:40 Kate Biberdorf? Like this baking, yeah, oh yeah, yeah.
29:42 Neil deGrasse Tyson? Where you need the milk, but you don't need as much milk.
29:44 Kate Biberdorf? Sure.
29:45 Neil deGrasse Tyson? So you'd have a reduced milk.
29:47 Kate Biberdorf? It just must have a lot of sugar though, if it's able to turn it into essentially a liquid candy, yeah.
29:52 Neil deGrasse Tyson? It's not just.
29:52 Kate Biberdorf? So it's a fat piece, so that must give it like the creaminess or something.
29:55 Neil deGrasse Tyson? Oh my god. When, when I saw that done and they opened the can, I was like. No, wait a minute now. Come on now. I thought, I thought they were.
30:02 Chuck Nice? I don't know. I think that's how they make Dos Eche de Leche, but.
30:04 Neil deGrasse Tyson? That's what I'm saying. It was very Dos Eche de Leche. Yeah, yeah.
30:08 Chuck Nice? Yeah, it's pretty cool.
30:09 Kate Biberdorf? That sounds good.
30:26 Chuck Nice? All right, here we go. This is Caleb Lillard, or Le Yard, you know, the double L in Spanish. Who knows?
30:37 Neil deGrasse Tyson? Caleb surely knows.
30:38 Chuck Nice? Yes, exactly. Caleb says, "Good day. This is Caleb Lillard from Dallas, Texas. Considering the increasing attention being given to the awareness of PFAS chemicals and how prevalent they are in everyone's lives, I honestly was just wondering if what is being spread through typical means of communication is more hyperbole, or if it should be associated with the level of gravity with which it has been paired." All right, so anyway, this question goes on and on, but really what he's saying is this. Are PFAS as dangerous as we think they are?
31:10 Neil deGrasse Tyson? Are these these things that never go away in the environment?
31:12 Kate Biberdorf? Right, that's the problem.
31:13 Neil deGrasse Tyson? I heard about, but I don't know anything about it.
31:14 Chuck Nice? They're called forever chemicals.
31:16 Kate Biberdorf? Mm-hmm, exactly.
31:17 Neil deGrasse Tyson? And what is the acronym for?
31:18 Kate Biberdorf? So it's per- and polyfluor-alkyl substances.
31:23 Neil deGrasse Tyson? Okay, let's keep it at PFAS.
31:24 Kate Biberdorf? PFAS, yeah.
31:26 Neil deGrasse Tyson? Dually abbreviated.
31:27 Kate Biberdorf? Yes, but the big piece is they have a carbon chain as the backbone, and then they're connected to fluorine.
31:33 Neil deGrasse Tyson? But wait a minute, doesn't everything have a carbon chain?
31:35 Kate Biberdorf? A lot of things, not everything.
31:36 Neil deGrasse Tyson? Aren't we just carbon chains?
31:38 Kate Biberdorf? Yes, we are just carbon chains too, but for PFAS, they've got this carbon backbone, and they're connected to fluorine, and they're really strong carbon fluorine bonds, really strong. And so that's what make them forever chemicals.
31:50 Chuck Nice? Because they can't be broken down.
31:51 Kate Biberdorf? Not easily.
31:51 Chuck Nice? Not easily.
31:52 Kate Biberdorf? Not easily.
31:53 Chuck Nice? Or it takes a long time to break them down.
31:54 Neil deGrasse Tyson? So those fluor- fluor-
31:56 Kate Biberdorf? Carbon CFCs.
31:57 Neil deGrasse Tyson? That's fluorocarbon, it's in there too.
32:02 Kate Biberdorf? Chlorofluorocarbon, so that usually is a much smaller molecule. And so it's like, my memory is that there's carbon and then it's attached to a couple things.
32:09 Neil deGrasse Tyson? From the refrigerant.
32:11 Kate Biberdorf? The ozone hole.
32:12 Chuck Nice? Killing the ozone.
32:12 Neil deGrasse Tyson? Okay, so I'm confusing the two.
32:14 Kate Biberdorf? It's okay.
32:14 Neil deGrasse Tyson? Go ahead.
32:15 Kate Biberdorf? So, but that's good to clarify the difference. So CFCs are much smaller, but they also are bad for the environment, they're gases. So PFOS here are much bigger molecules, and so if they get into our body because they're forever molecules and we can't break them down as easily, they stay in our body. And so that's a problem.
32:30 Neil deGrasse Tyson? But just to be clear, you have to quantify for me, how big is a big molecule?
32:36 Kate Biberdorf? Well, it ranges, and that's the problem. So there's 15,000 different molecules that can be considered a PFOS. And so that's the problem with this. It's really a generic term.
32:44 Neil deGrasse Tyson? At the end, we're just PFOS chemicals.
32:46 Chuck Nice? Yeah, I'm gonna say that's not hyperbole.
32:48 Kate Biberdorf? It's not hyperbole.
32:49 Chuck Nice? That is scary as hell.
32:50 Kate Biberdorf? Yes, and it's particularly troubling for women. We know that causes fertility issues. We know that in young women, so teenagers or girls who have yet to go through puberty, it is causing a delay in puberty. So we're seeing that issue coming up.
33:04 Neil deGrasse Tyson? But why can't we just poop it out?
33:07 Kate Biberdorf? Well, I think it's because it sticks with inside of our body. It must be forming some kind of like intermolecular force with the inside of our body, and so it's strong enough, because I wouldn't be surprised for, I'm speculating, but I wouldn't be surprised for fluorine to easily form some kind of intermolecular force with something in our body. They have three lone pairs on them, so it's really easy.
33:25 Neil deGrasse Tyson? Through the digestive tract.
33:26 Kate Biberdorf? Yeah, anywhere.
33:28 Neil deGrasse Tyson? Okay, so is it hyperbole? And, and wait, wait, back up. Where do these come from?
33:32 Kate Biberdorf? They are generated, we make them a lot of times, yeah. I would say, actually, I think all the times we make them. Yeah.
33:38 Neil deGrasse Tyson? For what?
33:39 Chuck Nice? Plastics, basically. Linings inside of bottles.
33:43 Neil deGrasse Tyson? So we're killing ourselves, basically. That wouldn't be the first time this has been a thing.
33:48 Kate Biberdorf? We have a pattern.
33:49 Neil deGrasse Tyson? We have a pattern, we're sensing the pattern. So it's in the environment?
33:52 Kate Biberdorf? It's in the environment.
33:53 Neil deGrasse Tyson? We ingest it and they never leave our bodies.
33:55 Kate Biberdorf? In, yeah, in theory, right? And I'm sure the smaller ones probably you can leave, but if the bigger they are, the more likely it is for them to form a bond inside of our bodies. And so it's problematic. Am I gonna try to eat PFOS? No. Am I gonna try to avoid it? Yes. So I don't think it's hyperbole. I think we really should avoid it.
34:10 Chuck Nice? Okay.
34:11 Neil deGrasse Tyson? Wow, good question. And if it's plastics and linings, there's no FDA label for PFOS, so you have to just read articles. That highlight it, right? So what's the biggest source of PFOS into our system?
34:23 Kate Biberdorf? Well, I don't want to point fingers, but a lot of times it has to do with chemical waste, right? And if we're not disposing it properly, then it can get into our water system.
34:30 Neil deGrasse Tyson? Why don't you want to point fingers?
34:32 Kate Biberdorf? Well, I mean, I should point fingers.
34:34 Chuck Nice? Because those companies are chemical companies. I'm just saying.
34:39 Neil deGrasse Tyson? Because they'll point their finger back at you.
34:40 Kate Biberdorf? And I want to get hired. I'd rather be on their side and then advocate for good science and maybe help them fix the problem. So that I want to be a chemical advocate.
34:49 Neil deGrasse Tyson? Play a blame game.
34:49 Kate Biberdorf? Correct, yes, I want to help.
34:51 Neil deGrasse Tyson? It's two different tactics.
34:52 Kate Biberdorf? Correct.
34:52 Neil deGrasse Tyson? Yes, yes. All right.
34:55 Chuck Nice? All right, okay.
34:55 Neil deGrasse Tyson? Well, thank you for that.
34:56 Kate Biberdorf? That's a good question.
34:57 Chuck Nice? Yeah, so this is Alan Rayer. Alan says, hello, Dr. Kate, privileged to follow you on Instagram.
35:03 Kate Biberdorf? Oh, thank you.
35:03 Chuck Nice? There you go. It's Alan from Lithuania here. What gives colors to the elements? Why does the color change in an element based on molecular bonds?
35:14 Neil deGrasse Tyson? Ooh, I love that.
35:15 Kate Biberdorf? Okay, so a couple of different answers here. It depends on the context of the question and what we're specifically looking at. So if we're looking at metals, just a generic metal in the neutral state, when we have an excitation, our electrons are going to move. They're going to go up in a level, think stairs. So they're quantized energy levels, so the electron will literally drink a Red Bull and then run up a bunch of stairs. That process is normal. But when they fall down the stairs, just like if we as humans fall down the stairs, we're going to scream and release energy. Electrons do the same thing. So as they fall down these stair steps, these quantized energy levels, they release energy in the form of visible light. And so if you have a big gap, you're going to see a high-energy light, blues and purples.
35:52 Neil deGrasse Tyson? Is that what he's asking? Was it more simple, just different things have different colors?
35:57 Kate Biberdorf? But that's why, though.
35:57 Neil deGrasse Tyson? Rather than glowing, that's a glowing metal, right?
36:01 Kate Biberdorf? It's an excited metal giving off light, right?
36:04 Chuck Nice? Like tungsten.
36:05 Kate Biberdorf? Like tung- okay, but yeah, yeah.
36:08 Neil deGrasse Tyson? Well, that's thermal, though.
36:09 Chuck Nice? That's thermal.
36:10 Kate Biberdorf? That's different, yeah. So, okay, but like, what about a quantum dot? So a quantum dot is something where if it's really small, like two nanometers, we're going to have a color of blue being emitted. But if it's a little bit bigger, with six nanometers, not that much bigger, we'll see a color of red. Yeah, exactly. And so there-
36:25 Neil deGrasse Tyson? It's the wavelength of the light.
36:26 Chuck Nice? That is giving off, that's really wild.
36:29 Kate Biberdorf? So.
36:29 Chuck Nice? Get out of here.
36:30 Kate Biberdorf? Yeah, that's how I think about it, is how just like it's emitting light and that's the color we see. So that's the context I usually-
36:34 Neil deGrasse Tyson? So what about all the things that are colorless?
36:37 Kate Biberdorf? Well, they are not emitting something.
36:39 Neil deGrasse Tyson? You know, like salt and sugar and flour and, you know, there's so many things that just have no color.
36:44 Kate Biberdorf? Well.
36:45 Neil deGrasse Tyson? The kitchen would be so much more interesting.
36:46 Kate Biberdorf? No color that we, that our human eyes can see. We only see the visible spectrum. So we can see from 400 to 700 nanometers.
36:53 Neil deGrasse Tyson? Physiology.
36:54 Kate Biberdorf? But if it's outside of that, we don't see it.
36:55 Chuck Nice? Stupid human eyes. Your big dumb human eyes can't see anything.
37:01 Neil deGrasse Tyson? Way she said it. Damn.
37:04 Kate Biberdorf? It's true.
37:04 Neil deGrasse Tyson? She acted like she could see outside that spectrum and the rest of it.
37:07 Kate Biberdorf? I can't.
37:08 Neil deGrasse Tyson? All right, keep going, Chuck.
37:09 Chuck Nice? All right, this is Daniel Gilligan. Daniel says, greetings, friends. Daniel here from Tasmania, Australia.
37:20 Chuck Nice? Okay.
37:21 Neil deGrasse Tyson? What was that?
37:21 Chuck Nice? That was my Tasmanian devil.
37:23 Neil deGrasse Tyson? Really? Is that even allowed anymore?
37:27 Chuck Nice? He says, how come water isn't the most flammable thing in the world, especially salt water? As separate elements, oxygen, hydrogen, and sodium are all very spicy when it comes to being flammable.
37:39 Neil deGrasse Tyson? Oh, yeah.
37:40 Chuck Nice? Or dangerous.
37:41 Neil deGrasse Tyson? But so let's start this off. What happens if I put a hunk of sodium in water?
37:44 Kate Biberdorf? Oh, you're going to see, uh, hydrogen gas is going to be evolved, which is extraordinarily flammable. It's an exothermic reaction, so usually it will ignite and you'll see a flame. Boom.
37:53 Neil deGrasse Tyson? That's, that's the chemist's way to say it.
37:55 Chuck Nice? It's a blow up.
37:56 Kate Biberdorf? Boom, yes.
37:57 Chuck Nice? Lot of, lot of.
37:57 Neil deGrasse Tyson? That's sodium, and sodium is in sort of sodium chloride, salt, and then we know.
38:01 Kate Biberdorf? But they're different. Those are different. Sodium that you throw into the water is a chunk of metal, and that's an oxidation state of zero, but sodium chloride has an oxidation state of plus one. And so the answer, the short answer to the question is where are the electrons next to these atoms? And so it's how they're sharing them or they're transferring the electrons is going to dictate how they're going to behave.
38:19 Chuck Nice? So, this is unbelievable stuff.
38:20 Neil deGrasse Tyson? Wait, wait, so, so the molecule, you cannot infer the property of the molecule.
38:27 Neil deGrasse Tyson? From the properties of the atoms that go into it.
38:30 Kate Biberdorf? You can if it has the same, if you're comparing like apples to apples. So if they are, if it's, if you're comparing CO2 versus SiO2.
38:39 Neil deGrasse Tyson? That's one way.
38:40 Kate Biberdorf? That's one way you can compare.
38:41 Neil deGrasse Tyson? However, I'm saying, like the questioner said, we know hydrogen is flammable. We know oxygen feeds flames. You put them together and it extinguishes flames.
38:51 Kate Biberdorf? Yes.
38:52 Neil deGrasse Tyson? That's weird.
38:52 Kate Biberdorf? It is weird, but they're so different though. Cause hydrogen is H2, it's two hydrogens bond together. So they're sharing two electrons. You've got oxygen has a double bond between it. So they're sharing four electrons. That's a really strong bond. And then water has one oxygen and two hydrogens. Those hydrogens are not next to each other. The oxygen's in the middle. Yeah. And oxygen is the second most electronegative atom that we know about. Meaning it pulls the electrons from its species. So in hydrogen, the electrons are being evenly shared. In water, the most of the electrons are completely up on the oxygen. And so it's all about where the electrons are and the reactivity.
39:25 Chuck Nice? So oxygen steals electrons.
39:27 Kate Biberdorf? Every time.
39:27 Chuck Nice? Like no matter, it's just basically, it's, it's the thief.
39:31 Kate Biberdorf? Mm-hmm.
39:32 Chuck Nice? Like, don't bring, don't bring your girl around oxygen.
39:34 Kate Biberdorf? That's the perfect analogy.
39:36 Chuck Nice? Don't bring your girl around oxygen. We know the deal. Oxygen is like Michael B. Jordan. Your woman is leaving with him tonight.
39:44 Kate Biberdorf? Yes. That's exactly it.
39:46 Chuck Nice? Okay.
39:49 Kate Biberdorf? I'm gonna use that in my classroom, by the way.
39:52 Neil deGrasse Tyson? Okay.
39:53 Chuck Nice? Wow.
39:54 Neil deGrasse Tyson? So Kate.
39:55 Kate Biberdorf? Yeah.
39:56 Neil deGrasse Tyson? I just, I understand that you have a podcast.
39:58 Kate Biberdorf? I do.
40:00 Neil deGrasse Tyson? An NPR podcast?
40:01 Kate Biberdorf? Yes, Seeking a Scientist.
40:03 Neil deGrasse Tyson? That's not all the right investments in any three of them going into it?
40:06 Kate Biberdorf? Yes, exactly. So we just dropped season two and our first episode of season two was about being in space. It was the DART mission. We interviewed Nancy Chabot.
40:13 Neil deGrasse Tyson? Double asteroid redirect test.
40:14 Kate Biberdorf? Yes, exactly. And so we go through the entire process from the beginning of the creation of the experiment, all the way to now what's happening and what their future missions are planned. It's awesome.
40:23 Neil deGrasse Tyson? So these are scientists active in something that you might be interested in as a listener?
40:27 Kate Biberdorf? Yes, and I would someday love to have a chemist on there. But yeah, it's been completely other than, than chemistry. Like we're, we're talking to someone who studies dogs and how you pick.
40:35 Neil deGrasse Tyson? Ask a chemist, just ask a scientist.
40:37 Kate Biberdorf? We're speaking to scientists.
40:38 Neil deGrasse Tyson? From any field.
40:39 Kate Biberdorf? Exactly. We've got this one woman who's doing research on puppies to figure out how you can determine what is the best service dog. Like, that's her research, is figuring out how to predict that. So we interview her, and so that's coming up in a couple of weeks.
40:48 Chuck Nice? The answer is it will not make a difference, because in 10 years, all service dogs will be autonomous robots that actually just guide you.
40:55 Kate Biberdorf? I love the golden retrievers. I want them to stick around.
40:58 Chuck Nice? Yeah, guess what? Robots don't poop.
41:01 Kate Biberdorf? Not yet.
41:04 Neil deGrasse Tyson? So it's filmed in your hometown, where you are, in Austin?
41:07 Kate Biberdorf? Yeah, I film out of Austin, and we interview scientists from all across the planet.
41:11 Neil deGrasse Tyson? Okay, so they, uh, virtually?
41:13 Kate Biberdorf? Virtually, yeah, it's all virtually, but the host city is actually Kansas City, so I gotta give a shout-out to KCR.
41:18 Neil deGrasse Tyson? Okay, KCR, okay. As in the public station model.
41:22 Kate Biberdorf? Correct.
41:22 Neil deGrasse Tyson? It's distributed, it's not one central creating point, and so they create it, and then it's shared with other
41:27 Kate Biberdorf? Correct.
41:28 Neil deGrasse Tyson? Other stations.
41:28 Kate Biberdorf? Yep.
41:29 Neil deGrasse Tyson? All right. Well, Kay, it's been a delight finding, we met over the, over the internet, but not in person. Uh, thanks for coming by.
41:35 Kate Biberdorf? Thank you for having me, it's so wonderful.
41:37 Neil deGrasse Tyson? And showing your media calendar with us, uh, here.
41:39 Kate Biberdorf? Thank you.
41:40 Neil deGrasse Tyson? All right, Chuck, always good to have you, man.
41:41 Chuck Nice? Always a pleasure.
41:42 Neil deGrasse Tyson? All right. In conversation with a chemist, which doesn't happen to me often, I'm just reminded how much of this world is enabled, empowered by chemists. What they have done for us has transformed our lives in every measurable way. Yet, at the end, it doesn't say, "By the time you use your cold pack, when you're done and your knee is a little better from this endothermic reaction that a chemist put in here, thank your nearby chemist." No, there isn't, there's no such instructions there. We just do it and take it all for granted. I should have a conversation with a chemist more often,
42:24 Neil deGrasse Tyson? so that I take less of what happens around me for granted. If you don't get to have a conversation with a chemist, next time you make anything in your kitchen, just sit and reflect on the fact that none of that would happen without chemistry. And that's a cosmic perspective, not only on the universe, but on your everyday life.
42:45 Neil deGrasse Tyson? Keep looking up.
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