The Magic of Chemistry with Kate the Chemist

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, you’re a personal astrophysicist.

We got a Cosmic Queries edition coming, all about chemistry, more than just a moment.

Chuck.

You doing man?

I’m doing well man, how you doing?

Okay, who’s that sitting next to you?

I got to tell you, only the most awesome chemist ever.

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.

Welcome.

Welcome to StarTalk.

Thank you.

And I have to, I need training on how to pronounce your last name, Biberdorf?

Biberdorf, perfect, yes, Biberdorf.

Biberdorf.

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 Biberdorf.

I’m a Biberdorf.

You’re a Biberdorf?

I’m a B-B-ber, I’m a B-B-ber.

Oh, I like it.

Yeah, B-B-ber.

My students call themselves the Biberdorks, so.

Oh, Biberdorks, good.

Yeah, so I’ll take that, too.

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.

Hook em horns, there it is.

So you built this huge following on social media, blowing shit up, is this what you do?

That’s what I do, yes.

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?

I highlight articles that I like or science.

Yes, apologies, yes, thank you.

But you know, highlight good research or hot science in the moment, so it’s easy to do that.

But I will-

Directing people.

Correct.

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.

Yes, yes, yes.

And so are these people who would not have otherwise been chemistry fans, do you think?

And they 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 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.

I have tools in my tool belt that I can use to get kids excited about it.

A calculator, it’s not as exciting.

They can write five to 10 digits.

All right.

So you have thought about what would excite them visually and intellectually.

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.

We’re looking at our hand right now.

But the research shows that.

Yes.

Rather than your life experience.

Yes, also true, yes.

That will also count as data, for sure.

For sure, oh for sure.

So you’re 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.

It’s actually insulating water.

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.

Let’s leave it at cows.

Let’s leave it at cows.

Leave it at cows.

It’s a flammable gas.

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, 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-

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 as smart, like the best citizens we possibly can have.

And how about your following?

They just want to see stuff blow up.

Blow up?

More, yes.

Or they can become like chemical engineers.

Yes, that’s for sure.

You must know, because they’ll write to you.

Yes, they do.

Yeah, so what do you know?

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.

But you never know when that will spark the curiosity that leads them to want to know what’s behind that explosion.

You know, my son started off with just chemistry and liked it so much that he’s going to school now for biochem.

Yeah, he’s gonna be a biochemist.

That’s what he tells me he wants to be.

You didn’t tell me that.

Yeah, and I told him, don’t be a biochemist, own a biochem company.

It’s not a bad idea.

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?

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 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?

I don’t know, I’m just making something up.

Well, maybe you melt it, so it’s a chocolate cake.

Something like that, there we go, okay.

A molten chocolate cake, okay.

Okay, yum, okay.

So then we have to heat it up, right?

So you’re gonna put it in the oven.

So it’s an energy source.

An energy source.

Going 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.

Mm-hmm.

Like…

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.

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.

Plus, I’m hearing these terms.

It’s easy to see now why people use the chemistry term to refer to human relationships.

With spontaneous reaction.

Right.

Chemical is in our chemistry.

Yes.

Use your words, not my words.

They are my words.

Astro, we don’t have that.

Very, 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 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.

That’s just the universe just being the universe.

Exactly.

Without your intervention.

Without my intervention.

So that’s a reaction that will happen on its own.

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?

Yeah, okay.

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.

No.

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.

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 one atmosphere.

And so those are the conditions where it would happen on its own naturally.

25 degrees Celsius.

That’s like a little higher than room temperature?

Yeah, 25 is what we call room temperature.

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.

Oh, 72, okay.

Okay, and then at one atmosphere.

At one atmosphere.

Okay, of pressure.

Of pressure, right.

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.

Your voice was stupid.

So we talk about gallium.

Gallium, so in the UK, it’s listed as a solid because the room temperature in the UK is colder than here.

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.

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.

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.

Yeah, your 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 mix.

The 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.

And that’s what they do when you make ice cream.

That’s why they use salt.

Yes, oh yeah, that’s correct.

Well, I think there’s a different reason.

Really?

Why?

If you make it by your hands, so you add a little bit of salt for it so that you can go back and forth, yeah?

Make ice cream in your hands?

With you put it in a Ziploc bag and then you put milk and sugar and vanilla.

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.

I’m a ice cream guy.

From way back.

All right.

I should weigh a hundred pounds more, but I emphasize just to wear off the ice cream.

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.

So now the medium is liquid.

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.

Okay, that makes sense.

It’s 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, because at first I was just like, all right, I finally got this guy.

I’m like, I know for a fact that it’s to lower the temperature, but that makes perfect sense.

Okay, so I would claim that salt and water does not lower the temperature.

That’s what I’m claiming.

Salt in water will always have freezing point depression.

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.

False.

Freezing point depression.

It will go down.

Delta T is equal to negative IKF times the molality.

If you put salt in water, it goes down by negative 1.86 degrees Celsius.

For?

It’s molality, so it would be moles of solute divided by kilograms of solvent.

Does it matter what kind of salt?

Definitely.

Definitely, yeah, it has to do with the Van’t Hoff factor.

Yeah, oh 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 an experiment tonight.

Do it, you will feel it.

You will feel it in your hand.

I’m doing an experiment.

That is cool, man, I’m too nervous.

The experiment gauntlet has been thrown down.

I promise you.

So how many degrees?

I challenge you, sir.

Ions at dawn.

Two Celsius max.

Two Celsius of what volume of salt?

I would make a super saturated solution.

So take a bunch of water, just dump salt in until you can see it at the bottom.

Stir, stir, stir, stir, stir.

And you’ll feel it.

You’ll physically feel the temperature go down.

So I got a super saturated, a lot of salt.

Just, yeah, but don’t do a lot of water.

Just do a cup of water and just shh, shh, shh, shh, shh.

Like, you’ll feel it.

Hello, I’m Alexander Harvey, and I support StarTalk on Patreon.

This is StarTalk with Dr.

Neil deGrasse Tyson.

Thank you, Dr.

Tyson.

Well, you have a huge fan base, and they heard you were coming on the show, and we solicited inquiries from them.

And what do you got here?

I haven’t seen them, have you seen them?

No, we don’t let them.

Oh, yeah, okay.

It’s a loving, high five.

They only ask things that, they’re really a great audience, they’re very curious, and they ask great questions.

And they pay for the privilege to ask a question.

Yes, they are Patreon members.

No, just for a month.

It’s $5 a month if you’re interested out there, which is 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, example, water extinguishing fire despite being made of highly flammable oxygen plus hydrogen, which we learn that’s the big tanks on the rockets that take the space shuttle to space.

The orange tank right there.

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 say, I’ll clean it up for him, trial and error.

Can you predict two new elements when they come together and they make something new, can you predict its properties?

We will try to.

So, the periodic table is organized based on size, but it’s also based on the chemical properties.

Size of 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 content.

I really like it here.

I gotta tell you, this electron shell just suits me perfectly.

I know, I don’t need anybody else to help.

I don’t know what it is.

I’m looking down at my nucleus.

I’m just as happy as I can be.

There it is.

Perfect.

That’s perfect, but you would expect everything.

So 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 chemical reaction.

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.

NH3, so that would be ammonia.

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.

Interesting.

That’s a fair answer.

I like that.

Oh, totally.

You can predict it, but then you test it.

You predict it and then you blow something.

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 limited funding.

So you want to put your eggs in the best basket.

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?

That’s the definition of science.

That’s what we do.

We watch 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.

I’m going to say, that’s a little more rare.

Next question.

We don’t find that word.

What do you have?

All right.

This is Mike Muhammad Khaki.

He says, greetings, Dr.

Tyson, Dr.

Biberdorf and Lord Nice.

Mike Khaki here from Berlin, 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?

So, activation energy is the minimum energy required for a chemical reaction to occur.

So, it’s sitting there, otherwise happy, 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 you need them to head on and then they do 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, 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.

So, do molecules have docking ports, basically?

Yes, but how do you configure them to know which docking ports are pointing which way?

Aren’t they littler than you can see?

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.

No.

That’s what spooked me.

Oh, no.

I thought she’s up there with tweezers, you know, putting one molecule…

That’s the dream.

I would love that.

To another.

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…

That would count as an activation energy, the speed that they collide.

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 at the right collision.

All of that is kind of looped up into activation energy.

Can you know that in advance, like from equations, or do 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, you are good at this.

Arrhenius.

This is like way back.

Yeah.

Arrhenius.

Yeah.

When was Arrhenius?

Oh, I don’t know.

I couldn’t give you a year.

Long, long enough ago that nobody is named Arrhenius.

That’s how long ago it was.

You have never met an Arrhenius in your life.

And Arrhenius doesn’t even have a middle or last name.

It’s just Arrhenius.

It’s like Cher.

I’m Arrhenius.

You know what?

I’m trying to figure out though 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 explained?

I would say the activation energy was the match.

I’m spitballing here.

It’s part of it.

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 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.

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 all that energy became the fire.

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 this happen, then not necessarily.

You can force things to go higher energy.

But usually, for what you’re saying.

But at the cost of putting the energy in.

Correct.

Yes.

All right.

That was cool, man.

Thanks a lot.

Can I do one clarification though?

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 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 is thermo.

At all.

And then how long.

And so from a standpoint of like going in the lab, I care about kinetics.

I want to know how long my reaction’s going to take.

Because can I go home?

Do I have to stay here all night?

Like, so kinetics actually matters.

So that’s why people care about activation energy.

So you want the experiment to be done before you go to sleep.

Yes.

Or before you die.

Right.

Or you can set it up and then go home and work it up in the morning.

That’s best case scenario.

This is Lawrence Harris.

And Lawrence says, Good day, gentlemen and gentlelady.

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.

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.

It’s like, oh, that’s way hotter than boiling water.

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.

I hate chemistry.

This is 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?

In the beginning, yes, but it’s not gonna be as much because it has a van’t-Hoff factor of one.

It doesn’t break apart.

That’s somebody else.

Yes, that’s somebody else.

Some other chemist of the past.

And so for the ionic species, when you put them in water, they break apart.

I want a Biberdorf 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 gonna 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 solid 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 to form?

It’s how you cool it.

That’s my understanding.

No, that makes sense.

My mom used to make candied sweet potatoes.

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…

Just pure sugar.

Just pure sugar.

No water, anything.

But you can’t do it too fast because you’ll just burn the sugar.

But what happens is the sugar very slowly, as you watch it, you can see it from the bottom, 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.

Your kitchen was a chemistry lab.

Oh, definitely.

Let me tell you something.

It was one of my favorite things to watch.

So kitchens are the thing.

Yes, every kitchen is a chemistry lab.

Thank you for making my point.

Yes.

Because it’s just I need some of this and some of that.

Yes, you’re cooking.

And so it lined up for you in all the cabinets.

Yeah, you know, I didn’t think of it until now, but that’s absolutely the case.

Especially baking.

Baking for sure is chemistry.

Cooking is also, there’s a time component.

You can have fun with it.

Baking is precise.

You need to be exact.

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 the egg becomes solid.

That’s kind of weird.

Well, it’s all about those proteins, right?

I think they’re opening up, and then they can form bonds between each other.

So I’ve seen this done, and I thought it was magic, where if you take sweetened condensed milk, 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.

You haven’t done that?

I have not done that.

I’ll try that.

I thought it would be experiment, but Kate the Chemist hasn’t done yet.

No.

So sweetened condensed milk.

So it must have a really high sugar content, right?

Yeah, because sweetened and condensed.

Yeah, use it for things like key lime pies.

All kinds of bacon.

Like this bacon.

Where you need the milk, but you don’t need as much milk.

So you’d have a reduced milk.

It just must have a lot of sugar though, if it’s able to turn it into essentially the liquid candy.

So it’s a fat piece, so that must give it like the creaminess or something.

When I saw that done and they opened the candy portion, I was like, no, wait a minute now.

Come on now.

I thought they were.

I don’t know.

I think that’s how they make dulce de leche.

That’s what I’m saying.

Yeah, I’m pretty sure.

All right, here we go, this is Caleb Lillard, or Le Yard, you know, the double L in Spanish, who knows?

Caleb surely knows.

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?

Are these these things that never go away in the environment?

I heard about it, but I don’t know anything about it.

They’re called forever chemicals.

And what is the acronym for?

So it’s PUR and polyfluoroalkyl substances.

Okay, let’s keep it at PFAS.

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, not everything.

Aren’t we just carbon chain?

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.

Because they can’t be broken down.

Not easily.

Not easily.

Not easily.

Or it takes a long time to break them down.

Wait, so those chlorofluorocarbons.

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 of things.

From the refrigerant that.

The ozone hole.

The ozone hole.

Okay, so I’m confusing the two.

It’s 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 gases.

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 a problem.

And this is a.

But just 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, 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.

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.

But why can’t we just poop it out?

Well, I think it’s because it sticks inside of our body.

It must be forming some kind of 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 flooring 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.

It’s through the digestive tract.

It gets absorbed in.

Yeah, anywhere.

Okay, so is it hyperbole?

And where did, wait, back up.

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.

On 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 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 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.

And 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?

And if we’re not disposing it properly, then it can get into our water system.

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.

Because they’ll point their finger back at you.

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.

Rather than play a blame game.

Correct, yes.

I want to help.

Two different tactics.

Correct.

Yes.

Yes.

All right.

All right, okay.

Well, thank you for that.

That’s a good question.

Yeah, so this is Alan Reyer.

Alan says, hello, Dr.

Kate.

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 a couple 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 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 isn’t 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.

Or is it more simple, just different things have different colors?

But that’s why, though.

Rather than glowing, that’s a glowing metal, right?

It’s an excited metal giving off light, right?

Like tungsten.

Okay, but, yeah, yeah.

Well, that’s thermal, though.

That’s thermal.

That’s different, yeah.

Okay, but what about a quantum dot?

So a quantum dot is something where if it’s really small, like two nanometers, we’re gonna 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.

Oh!

That’s the wavelengths of the light.

That is giving off, that’s really wild.

Get out of here.

Yeah, that’s how I think about it, is how it’s just like it’s emitting light and that’s the color we see.

So that’s the context I usually make.

Okay, so what about all the things that are colorless?

Oh well, they are not emitting something.

Or just white, you know, like salt and sugar and flour and there’s so many things that just have no color.

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 nanometers.

But if it’s outside of that, we don’t see it.

Your big dumb human eyes can’t see anything.

Wait, she said it.

She act like she could see outside that spectrum and the rest of us can’t.

All right, keep going, Chuck.

All right, this is Daniel Gilligan.

Daniel says, greetings, friends.

Daniel here from Tasmania, Australia.

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.

But 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.

A boom.

That’s the chemist way to say it.

It’s a blow up, blow up.

A lot of, lot of, yes.

That’s sodium, and sodium is in sodium chloride, salt.

And then we know how.

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 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 gonna dictate how they’re going to behave.

This is unbelievable stuff.

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 apples to apples.

So if you’re comparing CO2 versus SiO2.

That’s one way.

That’s one way you can compare.

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.

Yes.

That’s weird.

It is weird, but they’re so different though because 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 is 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.

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.

Yes, that’s exactly it.

I’m gonna use that in my classroom, by the way.

Wow.

So Kate, I understand that you have a podcast.

I do.

Yes, Seeking a Scientist.

That’s not all the right investments in any three.

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 redirect test.

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 some thing 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 pick.

You’re not asking chemists, you’re just asking scientists.

We’re seeking scientists.

Which could come 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.

So we interview her and so that’s coming up in a couple weeks.

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.

Oh, I love the golden retrievers.

I want them to stick around.

Robots don’t poop.

Not yet.

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 virtually.

Virtually, yeah, it’s all virtually, but the host city is actually Kansas City, so I gotta give a shout out to KCR.

KCR, okay.

Okay, as in the public station model.

Correct.

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, Kate, it’s been a delight finding, we’ve met over the internet, but not in person.

Thanks for coming by.

Thank you for having me, it’s so wonderful.

And sharing your media calendar with us here.

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 a 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, 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 every day.