The Magic of Chemistry with Kate the Chemist

Neil deGrasse Tyson
Welcome to Startalk, your place in the universe where science and pop culture collide. Startalk begins right now. This is startalk. Neil degrasse Tyson here, your personal astrophysicist. We got a cosmic queries edition coming.

All about chemistry. More on that in just a moment. Chuck. Hey. How you doing, man?

Chuck Nice
I'm doing well, man. How you doing? Okay. Who's that sitting next to you? I gotta tell you, only the most awesome chemist ever, ever, ever.

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. Chemistry. Kate the chemist. Hi. Welcome.

Neil deGrasse Tyson
Welcome to Startalk. Thank you. And I have to. I need training on how to pronounce your last name. Bieberdorf.

Beep, beep. Bieberdorf. Perfect. Yes. Bieberdorf.

Bieberdorf. So, like Justin Bieber and then Dorf. That's what I always say. No, that's wrong. The alter ego of his fan club.

That sounds like a fan club. I'm a Bieberdorf, Bieberdorf. I'm a Bieberdorf. Are you a Bieberdorf? I'm a beber.

Kate Biberdorf
Oh, I like it. Yeah. B Bieber. My students call themselves the Bieber dorks, so. Oh, Bieber dorks.

Neil deGrasse Tyson
Good. So I'll take that song. That's good. I like it. That's cool.

That's affectionate. That's affectionate. 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? That should be a thing, you know? And associate professor of chemistry, University of Texas, Austin. Yes. Hook em horn.

Oh, hook em horn. There it is. Okay. So you built this huge following on social media, blowing shit up. Is this what you do?

Kate Biberdorf
That's what I do, yes. That is so cool. Wait, wait. So how does that work on Twitter or in the medium where you don't have a video? It's difficult, for sure.

I mean, you can share a video on Twitter, so. Yeah, but on Twitter, I try to be more academic. Right. Highlight articles that I like or science. Twitter x.

Neil deGrasse Tyson
Excuse me. Yes, apologies. Yes, thank you. But you don't highlight good research or hot science in the moment, so it's easy to do that. Directing people.

Kate Biberdorf
Correct. Yes, yes, exactly. 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. 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.

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, by the.

Neil deGrasse Tyson
Way, anyone in your role who's also trying to do that with math has the same story. People hated their math class. They don't have fire. I at least have fire. I have liquid nitrogen.

Kate Biberdorf
I have tools in my tool belt that I can use to get kids excited about it. They got nothing. A calculator. It's not as exciting. You can write five to ten digits.

Neil deGrasse Tyson
All right, so you have thought about what would excite them visually and intellectually? Well, I was raised by psychologists. All of us agree on William James 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.

Kate Biberdorf
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. We're looking at her hand. Research shows that, yes. Rather than your life experience.

Yes. Also true. Yeah. We also count as data. For sure.

For sure. Oh, for sure. So you burning it like an alcohol or something? No. So 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 of the water. So it acts like a isolating way. Exactly, yes, exactly. So it acts like a lab coat. Then you grab bubbles that have been pumped full of methane.

Methane is very flammable. You hold onto it, you can light 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. But just to be clear, methane, such as the gas that comes out of cows.

Chuck Nice
Let's leave it at cow. Let's leave it at cow. Leave it at cow. It's a flammable gas. Right.

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. Yes. 100%. 100%? Yeah.

Kate Biberdorf
I mean, the point. At the end of the day, my goal is for students to become good scientists. Only 5% of those students become chemistry majors. So I really want them to be educated voters. I want them to be able to have your class.

In my class, you have 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. And how about your following?

Neil deGrasse Tyson
They just want to see stuff blow up. Blow up more. Yes. So they can become, like, chemical engineers? Yes, that's for sure.

You must know. Cause they'll write to you. Yes, they do. So what do you know? They like the explosions.

Kate Biberdorf
They like the really quick, fast things. They do not want me to drone on about the structure of an atom. But you never know when that will spark the curiosity that leads them to want to know what's behind that explosion. Yeah. Yeah.

Neil deGrasse Tyson
There it is. My son started off with just chemistry and liked it so much that he's going to school now for biochemistry. Yeah. He's going to be a biochemist. That's what he tells me he wants to be.

You didn't tell me that. And I told him, don't be a biochemist. Own a biochem company.

Kate Biberdorf
Not a bad idea. Seriously, 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?

Ooh. 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.

Neil deGrasse Tyson
You put chocolate chips in cake? I don't know. I'm just making something. Cookie? Well, maybe you melt it.

Kate Biberdorf
So it's a chocolate cake. Okay, good. There we go. Okay. A molten chocolate cake.

Neil deGrasse Tyson
Okay, that's good. That's good. Okay. Yum. Okay, so then we have to heat it up, right.

Kate Biberdorf
So you're gonna put it in the oven. So that's an energy source. An energy source into the cake. 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. 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. Like.

Chuck Nice
Like iron turning into rust. Yes. So other things can happen even after you're done doing what you're doing? Oh, yeah. So they would happen without your intervention.

Kate Biberdorf
Correct. So that goes back to being a spontaneous reaction. And so, I'm gonna jump into some thermodynamics. So, pull me back if I go too far here. Okay.

Okay. 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.

Neil deGrasse Tyson
Chemicals in our chemistry. Use your words, not my words. They are my words. Astra, we don't have that. You got all the words for relationships.

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 going to give off heat as it goes from the reactants to. 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.

Neil deGrasse Tyson
That's just the universe just being the universe. Exactly. And that's your intervention. Without my intervention. So, that's a reaction that will happen on its own.

Kate Biberdorf
So they don't even need me to do this. Okay. So, does the formation of diamonds count as happening on its own? If that needs pressure and temperature and time. That's what I was gonna say.

What are your conditions? So, I would say, yes, over time. I just can't put a lump of carbon on my table and come back and wait for it to become a diamond. Not for us. We will never see that.

Neil deGrasse Tyson
Right? No. 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.

Kate Biberdorf
Sorry. 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. 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 1 atm. And so those are the conditions where it would happen on its own.

Neil deGrasse Tyson
25 degrees Celsius, that's like a little higher than room temperature. Yeah, 25 is what we call room temperature. Oh, I didn't know that. Yeah, 25 c in chemistry, at least that's how we define that. And so that's probably like, I don't know, 73, 75.

Yeah, it's a little above 72. Oh, 72, okay. It's a little above 73. That's what he said. Okay, cool.

Yeah, yeah, yeah. Okay. And then at 1 ATM. At 1 ATM and pressure of pressure. Right.

Kate Biberdorf
And so that's how our chemical reactions occur here on earth, because those are what our standard conditions are. 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, but in the UK, it's listed as a solid.

But that's. Gallium. Gallium, gallium, gallium. I was like, beryllium. Excuse me.

It's okay. Sorry, her voice was stupid. No, so we talk about gallium. Gallium, gallium. So, in the UK, it's listed as a solid because the room temperature in the UK is colder than here.

Chuck Nice
Wow. And so. 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. That's it, yes. Very cool. So one last thing about these exothermic reactions.

Neil deGrasse Tyson
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, smash, it becomes cold.

It becomes cold. So people like you have something to do with that? Oh, thank you. Yes. I'll take credit for that.

Kate Biberdorf
Absolutely, yeah. Your people, my people, 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. Oh, yeah, absolutely.

And so usually how those things work is there's one pouch that's filled with something, and then there's another pouch in the inside, and so you're breaking the two pouches and allowing for the two. Things to match a membrane between them. Right, exactly. It's a really thin membrane, and just with a little bit of force, we can break it. 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. Right, okay. And that's what they do when you make ice cream.

Chuck Nice
That's why they use salt, yes. Oh, yeah, exactly. That's correct. Well, I think there's a different reason. Really?

Neil deGrasse Tyson
Yeah. Why? 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. Make ice cream in your hands.

Kate Biberdorf
You put it in a ziploc bag, and then you put milk and sugar. And vanilla, or 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. I'm an ice cream guy. Okay. From way back.

Neil deGrasse Tyson
All right, I should weigh 100 pounds more, but I exercise to wear off the ice. Just enough to wear, just so I can eat ice cream. Got your bucket. It's filled with ice, right. 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. All right, you put salt on the ice. The ice melts at that temperature. Right. So now the medium is liquid.

Chuck Nice
Liquid. And the liquid is now touching every single part of the cylinder. But it is the same temperature. At the same temperature as the ice. Correct.

Neil deGrasse Tyson
Way better at sucking the heat out than just solids that it's turning within. All right, I'll accept that cogent argument you have made. That's all I'm saying. Which I should have known. Cause at first I was just like, all right, I finally got this guy.

Chuck Nice
No, I'm like, I know for a fact that it's to lower the temperature, but that makes perfect sense. Yeah, yeah. So I would claim that salt in water does not lower the temperature. That's what I'm claiming. Salt in water will always have freezing point depression.

Kate Biberdorf
That is a thing. We can measure that. I get that. But if water's at a given temperature and salt is just the salt, I'm gonna assert that you put the salt in the water. Nothing happens to the temperature.

Neil deGrasse Tyson
That's what I'm gonna claim. False freezing point depression. It will go down. Delta T is equal to negative ikf times the molality.

Mic drop. If you put salt in water, it goes down by negative 1.86 degrees celsius per. Yeah, that is, it's molality. So it would be moles of solute divided by kilograms of solvent. Does it matter what kind of salt?

Kate Biberdorf
Definitely, yeah. It has to do with the van't hoff factor. Okay. Yeah, but at home you just have table salt. Correct.

And so it has a van t hoff factor of two. So will this work for table salt? Absolutely, yes. Because when you put sodium chloride in water, it's gonna break apart into the ions. I'm doing the experiment tonight.

Do it. You will feel it. You will feel it in your hand. I'm doing an experiment. That is cool, man.

Chuck Nice
I love it. The experiment gauntlet has been thrown down. I promise you. Okay, so how many degrees? I challenge you, sir.

Ions at dawn. Two celsius max. Two celsius max of what? Volume of salt? I would make a super saturated solution.

Kate Biberdorf
Oh, yeah. So take a bunch of water, just dump salt in until you can see it at the bottom. Stir, stir, stir, stir, stir, stir. And you'll feel it. You will physically feel the temperature go down.

Neil deGrasse Tyson
So I got a super saturate. It's a lot of salt. Just. Yeah, but don't do a lot of water. Just do a cup of water.

Kate Biberdorf
Like, you'll feel it.

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Chuck Nice
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Neil deGrasse Tyson
Well, you have a huge fan base, and they heard you were coming on the show, and we solicited inquiries from them. Exciting. And what do you got here? I haven't seen them. Have you seen them?

Chuck Nice
Nope, we don't let them. Oh, yeah. Okay. It's a loving, yeah, they only ask. Things that, they're really a great audience and they're very curious, and they pay.

Neil deGrasse Tyson
For the privilege to ask a question. Yes, they are our Patreon members. No, just per month. It's $5 a month. If you're interested out there and you.

Want to join the cheapest membership of anything you would ever have. 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.

Chuck Nice
Example, water extinguishing fire, despite being made of highly flammable oxygen plus hydrogen. Right, which we learned. That's the big tanks on the rockets that take these space shuttles in space. Yeah, the orange tank. Right.

Here 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'd love that. I'll say, I'll clean it up for em.

Trial and error. Can you predict two new elements? When they come together and they make something new? Can you predict its properties? Yeah, we will try to.

Kate Biberdorf
So the periodic table is organized based on size, but it's also based on chemical properties. Size, meaning size of the nucleus, size of the whole. The whole atom. The whole atom. 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, they're happy in and of themselves.

They're satisfied. There's got to be some psychological. You're content. I really like it here. I gotta tell you, this electron shell just suits me perfectly.

Neil deGrasse Tyson
I know. I don't need anybody else to help. You know, I'm looking down at my nucleus. I'm just as happy as I can be. There it is, the right hand column, personified by Chuck.

Kate Biberdorf
Yes. Okay. That's right. 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 in a reaction, in a chemical, in a reaction, if it's bonded to the same partnership. So I would compare nh three with ph three, and I would expect them to behave similarly, not the exact same way.

So that would be ammonia, ammonia versus ph three, 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. Interesting.

Neil deGrasse Tyson
That's a fair answer. I like that. Oh, totally. Yeah. Yeah.

Kate Biberdorf
You can predict it, but then you test it, right? You predict it and then you blow something up. Yeah. But I bet people before you understood the periodic table, there must have been a lot of trial and error, of. Course, but 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 have a limited funding, so you want to put your eggs in the best basket. Yeah.

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.

Kate Biberdorf
To figure out that's the definition of science. That's what we do. We stare. Right? I mean, right?

We watch us something, we try to detect patterns. That's all we learn in grad school. We don't use AI, we use ni. Natural intelligence. Oh, okay.

Chuck Nice
Right on this bump, I'm gonna say that's a little more rare. All right, next question. Who do you have? All right, this is Mike Muhammad Khaki. He says, greetings Doctor Tyson, Doctor Bieberdorf and Lord Nice.

Mike khaki here from Berlin in Germany. Can you explain the role of activation energy in a chemical reaction and how it influences the rate of reaction? I love that. That's a beautiful question. What is activation energy?

Kate Biberdorf
So activation energy is the minimum energy required for a chemical reaction to occur. So it's sitting there otherwise happy. Yeah. Until you put energy in it, then it runs away? Yes, 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. In whatever way is your intent. Right, exactly.

And so there's based on the collision. So the orientation of the molecules matters. If it's, if you need them to hit head on and then they do like side by side, you might not have the collision. Wait a minute. You know how the molecules are oriented?

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.

Chuck Nice
Molecules have like docking ports, basically. I'm okay with that. Yeah. Yes, but how do you configure them to know which docking ports are pointing which way? Aren't they littler than you can see?

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. But how do you control that? We can't. Oh, okay.

Neil deGrasse Tyson
No, that's what spooked me. Oh, no. I thought she's up to a tweezers. You know, putting one molecule that's the dream. I would love that.

Kate Biberdorf
All right. 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. 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 as an activation energy, the speed. Correct. Part of it. It's part of it?

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 atom. And can you know that in advance, like, from equations, or would you measure that 100%?

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 t one minus one over t two. Arrhenius. Wow.

Chuck Nice
You are. This one's good at this. I had to find. This is, like, way back. Way back, yeah.

Neil deGrasse Tyson
Arrhenius. Yeah. And so when was Arrhenius? Ooh, I don't know. I couldn't give you a year long.

Chuck Nice
Long enough ago that nobody is named Arrhenius. That's how long ago it was. You have never met an arrhenius in your life. An arrhenius doesn't even have a middle or last name. He's like, cher.

Neil deGrasse Tyson
I'm Arrhenius. I love that. Yeah. Yeah. You know what I'm trying to figure out, though?

Chuck Nice
That 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 said, I would. Say the activation energy was the match. I'm spitballing here, but I'm thinking.

I'm just thinking. I'm just saying, 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 h two o. 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. 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, but you release the energy. Right. Right. Is that a fact? Did I say that right?

Kate Biberdorf
If it's favorable, yes, if it's favorable, you're going from higher energy to lower energy. But if we had to force that, if we were in, like, extreme conditions to make the happen, then not necessarily you can force things to go higher energy, but usually the cost of putting. The energy in, correct? Yes. Okay.

Neil deGrasse Tyson
All right. That was cool, man. Thanks a lot. Can I do one clarification? Okay, so, activation energy is about kinetics.

Kate Biberdorf
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 going to take. So you need enough energy, and it can guide us to figure out rate constants. And so often people combine these two things, but it's, will it happen as thermal at all?

At all. And then how long? And so, from a standpoint of, like, going into a lab, I care about kinetics. I want to know how long my reaction is going to take, because, can I go home? Do I have to stay here all night?

Like, so the kinetics actually matter. So that's why people care about activation energy. So you want the experiment to be done before you go to sleep? Yes. Or you die.

Right. Or you can set it and then go home and work it up in the morning. That's best case scenario. Okay. All right.

Chuck Nice
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.

Neil deGrasse Tyson
What's up with that? What is going on there? And by the way, worst candy ever. And also, there it is, a liquid. And you think, oh, let me just taste that.

Chuck Nice
Look at that. I burn not only my finger, I don't have a finger. I have no tongue. I hate candy now. This is just a disaster.

Neil deGrasse Tyson
I hate chemistry. Terrible. So we talked earlier about dissolving salt in water, 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, will that also drop the temperature?

Kate Biberdorf
In the beginning, yes, but it's not gonna be as much because it has a vant hoff factor of one. It doesn't break apart. That's somebody else? Yes, that's somebody else. Some other chemist took the past.

And so for the ionic species, when you put them in water, they break apart. I want a bieb dwarf factor. Nice. Nice. I don't have one.

You don't have a factor? I don't have one, no. You can't hang unless you have a factor. I know. All right, 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 kind of mess with that. So what's interesting about sugar is that when you heat it up, it's going to dissolve, you're going to increase the solubility.

And so that's. That's true for anything. 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. So if you boiled soda, then the gas just comes out, it doesn't stay dissolved in. Boom. Got it.

It's the opposite. Exactly. So when you add sugar in, you're going to heat it up, and then it's going to dissolve. And so that's why you heat it. But it's the cooling process that really dictates whether or not you're going to have, like, a smooth candy or the hard candy, like rock candy.

So if you don't touch it at all, you're going to allow for your system to kind of minimize the entropy lock into these beautiful cages, give it. A chance to do it all by itself. Exactly. Yes. Let it settle.

And then you'll get these gorgeous rocks, 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 kind of shake it up a little bit, you can't form those gorgeous crystals. And so you're not going to get rock candy. You're going to 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? So it's not how you heat it, it's how you cool it? That's my understanding. No, that makes sense.

Chuck Nice
My mom used to make candied sweet potatoes. Oh. And the way you start the candy process is. And they called 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. Just pure sugar? Just pure sugar. No water?

No water. But you can't do it too fast because you'll just burn the sugar. Burn the sugar. 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 a syrupy fudge, and then when it cools, it just becomes, like, a little, like, caramel coating over top of the sweet potatoes. So your kitchen was a chemistry lab. Oh, definitely. Let me tell you something. It was one of my favorite things to watch.

Neil deGrasse Tyson
So kitchens are the thing. Yes. Every kitchen is a chemistry lab. Thank you for making my point. Yes.

Cause it's just, I need some of this and some of that. Yes, you're good. And it's all lined up for you. And all the cabinets. Yeah.

Chuck Nice
You know, I didn't think of it until now, but that's absolutely the same. Especially baking. Baking, for sure, is chemistry. Cooking is also. There's a time component.

Kate Biberdorf
You can have fun with it. Baking is precise. You need to be exact. Yeah. But if you take albumin from an egg, which is otherwise transparent, then you heat it.

Neil deGrasse Tyson
Not many things will you heat, do. They then become solid. But the colorless part, egg becomes solid. That's kind of weird. Well, it's all about those proteins, right?

Kate Biberdorf
I think they're opening up, and then they can form bonds between each other. Right. 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.

Chuck Nice
Wow. Okay. You haven't done that. I have not done that. Oh, my gosh.

Kate Biberdorf
I'll try that. I thought about the experiment to gate the chemist. Hasn't done yet. No. So sweetened condensed milk.

Okay. Okay. So it must have a really high sugar content. Yeah. And it's condensed.

Neil deGrasse Tyson
Yeah. Use it for things like key lime. Pies, all kinds of bacon, like this bacon? Yeah. Well, you need the milk, but you don't need as much milk.

Kate Biberdorf
Sure. So you'd have reduced milk. It just must have a lot of sugar, though, if it's able to turn it into essential oil. Yeah, but with the milk. Yeah.

It's not just so it's a fat piece. So that must give it, like, the creaminess or something. Oh, my God. I saw that done. And they opened the can of pour.

Neil deGrasse Tyson
I was like, no, wait a minute, now. Come on now. I thought. Yeah, I thought they were. I don't know.

Chuck Nice
I think that's how they make dulce de leche, but that's what I'm saying. Yeah, I'm pretty dolce de leche. Yeah, yeah, yeah. It's pretty cool, man. That sounds good.

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Terms apply. Learn more@americanexpress.com with amex all right, here we go. This is Caleb Lillard. Or Lillard, you know, the double l in. He's spanish.

Who knows? Caleb surely knows. Yes, exactly. Go ahead. 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? Are these these things that never go away in the environment? Right.

Kate Biberdorf
That's the problem. Exactly. I heard about. I don't know anything about it. They're called forever chemicals.

Neil deGrasse Tyson
And what is the acronym for. So it's per and polyfluoroalkyl substances. Okay, let's keep it at PFAS. PFAS? Yeah.

Dually abbreviated, yes. But the big piece is they have a carbon chain as the backbone, and then they're connected to fluorine. But wait a minute. Doesn't everything have a carbon chain? A lot of things.

Kate Biberdorf
Not everything. Aren't we just carbon chains? 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 chemical. Because they can't be broken down. Not easily. Not easily.

Not easily. Or it takes a long time. Wait, so those chlorofluoro carbon cfcs, that's fluorocarbon. It's in there, too. 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 from the refrigerant. Okay, so I'm confusing the two. It's.

Neil deGrasse Tyson
Okay, go ahead. So. But that's good to clarify the difference. So cfcs are much smaller, but they also are bad for the environment. They're guesses.

Kate Biberdorf
So pfas 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 what the problem. And this, to be clear, you have to quantify for me, how big is a big molecule? Well, it ranges, and that's the problem.

So there's 15,000 different molecules that can be considered a pfas. And so that's the problem with this. It's really a generic term. At the end, we're just PFAs chemicals. Yeah.

Chuck Nice
I'm gonna say that's not hyperbole. It's not hyperbole. That is scary as hell. Yes. And it's particularly troubling for women.

Kate Biberdorf
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. Why can't we just poop it out?

Well, I think it's because it sticks with inside of our body that 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 through the digestive tract anywhere. Okay, so is it hyperbole and.

Neil deGrasse Tyson
Wait, Becca, where do these come from? They are generated. We make them a lot of times. Yeah, I would say, actually, I think all the times we make them for purpose. Yeah.

For what? Plastics, basically, linings inside of bottles. So we're killing ourselves, basically. That wouldn't be the first time this has been a thing. We have a pattern.

We have a pattern. We're sensing the pattern. So it's in the environment. It's in the environment. We ingest it.

And they never leave our bodies. 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.

Kate Biberdorf
And so it's problematic. Going to try to eat pfas? No. Am I going to try to avoid it? Yes.

So I don't think it's hyperbole. I think we really should avoid it. Okay. Wow. Good question.

Neil deGrasse Tyson
If it's plastics and linings, there's no FDA label for PFAS, so you have to just read articles that highlight it. Right. So what's the biggest source of pfas into our system? Well, I don't want to point fingers, but a lot of times it has to do with chemical waste. Right.

Kate Biberdorf
And if we're not disposing it properly, then it can get into our water supply. Why don't you want to point fingers? Well, I mean, I should point fingers. Because those companies are chemical companies. I'm just saying, go point their finger back.

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. Got it. So that I want to be a chemical advocate, I want to play a blame game. Correct?

Yes. I want to help. Two different tactics, correct? Yes. Yes.

Neil deGrasse Tyson
Yes. All right. All right. Okay. Well, thank you for that.

Kate Biberdorf
That's a good question. Yeah. So this is Alan Rayer. Alan says hello. Doctor Kate.

Chuck Nice
Privileged to follow you on instagram. It's Alan from Lithuania here. What gives colors to the elements? Why does the color change in an element based on molecular bonds? Okay, so couple different answers here.

Kate Biberdorf
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 level. 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 purple. That's what he's asking. Was it more simple?

Neil deGrasse Tyson
Just different things have different colors. But that's why, rather than glowing, that's a glowing metal. Right. It's an excited metal giving off light. Right.

Kate Biberdorf
Like Houston, like tongue. Okay. But, yeah. Yeah. Well, that's thermal.

Chuck Nice
That's the other. 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 2 nm, we're gonna have a color of blue being emitted.

Kate Biberdorf
But if it's a little bit bigger, with 6 nm, not that much bigger, we'll see a color of red. Yeah, exactly. And so there's the wavelength of the. Light that is giving. That's really wild.

Chuck Nice
Get out of here. 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 think. So. What about all the things that are colorless?

Kate Biberdorf
Oh, well, they are not emitting something. Which is white, like salt and sugar and flour. And, you know, there's so many things that just have no color. Well, the kitchen would be so much more interesting. No color that we.

That our human eyes can see. We only see the visible spectrum. So we can see from 400 to 700 nm. But if it's outside, we don't see it. Human eyes, your big, dumb human eyes can't see anything.

Neil deGrasse Tyson
The way she said it. Damn. It's true. She act like she could see outside that spectrum, and the rest of us can't. I can't.

All right, keep going, chuck. All right. This is Daniel Gilligan. Daniel says, greetings, friends. Daniel here from Tasmania, Australia.

Chuck Nice
Okay. What was that? That was my tasmanian devil. Really? Is that even allowed anymore?

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 or dangerous. So let's start this off. What happens if I put a hunk of sodium in water? Oh, you're going to see 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.

Kate Biberdorf
Boom. That's the chemist's way to say that's sodium. And sodium is in sodium chloride, salt. And then we know, 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. Dictate how they're going to behave.

Chuck Nice
So this is unbelievable stuff. Wait, wait. So the molecule, you cannot infer the property of the molecule from the properties of the atoms that go into it. You can if it has the same. If you're comparing, like apples to apples.

Kate Biberdorf
So if they are, if it's. If you're comparing CO2 versus sio two, that's one way. That's one way you can compare it. However, I'm saying, like the questioner said, we know hydrogen is flammable. We know oxygen feeds flames.

Neil deGrasse Tyson
You put them together and it extinguishes flames. Yes. That's weird. It is weird, but they're so different, though. Cause hydrogen is h two.

Kate Biberdorf
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, most of the electrons are completely up on the oxygen. And so it's all about where the electrons are in the reactivity. So oxygen steals electrons every time. Like, no matter. It's just basically, it's a thief.

Chuck Nice
Like, don't bring your girl around oxygen. That's the perfect analogy. Don't bring your girl around oxygen. We know the deal. Oxygen is like Michael B.

Jordan, your woman is leaving with him tonight. Stop. Yes, that's exactly it. Okay. I'm gonna use that in my classroom, by the way.

Neil deGrasse Tyson
Okay. Wow. So, Kate. Yeah. I just.

I understand that you have a podcast. I do an NPR podcast. Yes. Seeking a scientist. We just got all the right investments in anything going into it.

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. Double asteroid redirector.

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. So these are scientists active in something that you might be interested in as a listener. Yes.

And I would someday love to have a chemist on there, but yet it's been completely other than chemistry. Like, we're talking to someone who studies dogs and how you do it. Ask the chemist. It just asks a scientist. Ask a scientist.

Neil deGrasse Tyson
We're seeking from any field. 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.

Kate Biberdorf
So we interview her. And so that's coming up in a couple years. The answer is, it will not make a difference, because in ten years, all service dogs will be autonomous robots that actually just guide you. I love the golden retrievers. I want them to stick around.

Yeah. Guess what? Robots don't poop. Not yet. Not yet.

Neil deGrasse Tyson
So it's filmed in your hometown, where you are in Austin? Yeah. I film out of Austin, and we interview scientists from all across the planet. Okay. So they virtually.

Kate Biberdorf
Virtually. Yeah, it's all virtually, but the host city is actually Kansas City. So I gotta give a shout out to KCU R. Okay. Okay.

Neil deGrasse Tyson
As in the public station model, it's distributed. It's not one central creating point, and so they create it, and then it's shared with other stations. All right, well, okay. It's been delight. Finally.

We met over the Internet, but not in person. Thanks for coming by. Thank you for having me and sharing. Your media calendar with us here. Thank you.

All right, Chuck. Always good to have you, man. Always a pleasure. 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 the chemist more often 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 to 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. Keep looking at it.

Chuck Nice
Keep looking at it.

The Magic of Chemistry with Kate the Chemist

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1: Introduction to Kate the Chemist

2: The Role of Emotions in Learning

3: Practical Chemistry Demonstrations

4: The Educational Philosophy

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