Hi everyone!
I'm Abby Brown.
It's such a pretty day to be outside and enjoy this
big, beautiful world.
Did you know that everything we see,
everything we touch, even this water, even me,
everything is made up of matter.
Matter is anything that takes up space.
Chemistry examines matter.
Like what is matter made of?
How does matter change?
And since matter is everywhere, chemistry has
limitless possibilities.
Go Beyond with Iowa PBS and the Science Center of
Iowa as we discover chemistry.
♪♪
I am so excited because we
are about to go on an awesome science adventure.
My friend Allison from the Science Center of Iowa is
going to show us some awesome experiments that
will open our eyes to the fascinating world of
chemistry.
Take it away, Allison!
♪♪
Hi friends!
Have you ever wondered why the grass is wet in the
morning?
Or why an ice cream cone melts when it's a really
hot day outside?
Or even my favorite, how cookies become so
delicious when they are made out of so many
different individual items?
Well, that's because of something called
chemistry.
Chemistry is the study of matter and matter is all
around us.
And today we're going to explore chemistry together
and learn a little bit more.
♪♪
(liquids bubbling)
I mentioned that
chemistry is the study of matter.
Matter comes in all different shapes and
sizes.
In fact, it is anything that takes up space.
So the cart here in front of me, that's a solid.
It's hard, you can't go through it very easily.
We also have liquids, like water that you have
experienced before.
Or even something that is around you that you don't
often think about, gases, in the air.
So if you take a deep breath in --
(inhales)
-- and you blow it out --
(exhales)
-- you can feel
that matter moving through your lungs and out into
the air around you.
So now that we understand that matter comes in three
basic states, that solid, liquid and gas, we need to
understand how it changes between those different
states.
♪♪
Matter is made of these itty bitty little
things called atoms.
And atoms are part of this really special table
called the Periodic Table of Elements.
Each of these squares and letters represent a very
special type of atom.
And these atoms make up everything in the
universe.
And when you put certain types of atoms together
you get different types of materials.
♪♪
So, for example, if you take two hydrogen
atoms and an oxygen atom, you make something called
water.
So you've had water around you all the time.
We have water, so you can see hydrogen, hydrogen,
oxygen, water.
Now, we're going to explore what happens to
molecules when you give them more energy.
So here we're going to pretend that my ping pong
ball is a molecule.
And inside here I have a variety of molecules and
right now they don't have a lot of energy.
I want you to observe with your eyes and notice what
happens as I turn on my fan and I give those ping
pong balls more energy.
You ready?
Here we go!
♪♪
Sometimes it takes a little bit of time to
get an experiment up and going.
♪♪
So here those ping pong balls are moving
around just a little bit more and then they get
more and more and more energy.
And as they go from being really close together,
those molecules are moving as we can think of it --
-- from being really close together as a solid, to
when they were moving around a little bit more
as a liquid, and then when they were bouncing around
a lot and had a lot of space and a lot of energy
together as a gas because energy comes in different
types just like heat.
So if you ever think of yourself on a cold day
lots of times you'll come in really close and you
want to be close together, your molecules do the same
thing.
Molecules that are cold they want to be close
together, they don't have a lot of energy.
And then as they get more and more energy they like
to move around and spread out.
So we're going to show you a couple of experiments
today with physical reactions.
That's what it's called when you change between a
solid, a liquid and a gas.
♪♪
So before we start we always want to do
safety first.
I'm going to put on my goggles to protect my
eyes.
I'm going to put on my gloves to protect my
hands.
And if you're ever doing experiments at home, you
need to do the same thing, you need to protect
yourself.
You need to protect your eyes, you need to protect
your hands, you need to protect your area in which
you're going to do experiments and most
importantly need to check with an adult because
they'll make sure that what you're using is safe
for you to do.
So back to physical reactions.
Remember, we are thinking about molecules.
And the first one we're going to go back to water,
that two hydrogens and that one oxygen.
And in its solid form it is ice.
You've had ice in your drinks before, maybe in
your water just to make it a little bit cooler.
Whoops!
This is very slippery because it's already
transitioning.
Ice at 32 degrees is a solid, so that water,
those molecules are really close together.
By being in this room we're adding more heat and
more energy and so those molecules are starting to
warm up and take up a little bit more space and
so it's starting to melt.
It's going from a solid to a liquid.
Then if we left this ice cube out here long enough
and it turned all the way to water as its liquid and
then if we added more heat and we gave it more time,
all this water here would actually turn into water
vapor, which is the gas form of water.
So we are thinking about how things gain energy and
they change shape.
And you can do this in reverse too.
You can take away energy and change shapes.
So you can go from water vapor and make that cooler
and take away that energy and go down to water
liquid.
So in the mornings when you see dew on the grass,
that is going from that water vapor to that water
liquid.
And then if you put that water liquid in the
freezer you get to solid, that ice cube.
So those are things that we can think about.
Now, different types of matter react differently
to different amounts of energy.
So remember, we're thinking of energy as
being heat.
And here I have another solid but it's even colder
than my ice.
This is 109 degrees below zero.
This is dry ice.
Dry ice is actually made out of different
molecules.
These molecules are made out of carbon dioxide.
So we have one carbon atom and two oxygen atoms.
And in its solid form it's really, really cold, those
molecules are really close together.
But as we bring it out into this room, which is a
lot warmer than that dry ice, those molecules heat
up so rapidly that they just skip the liquid form
and they go straight to the gas.
So that's a process called sublimation, it's a phase
change.
So we're going from one phase of matter, a solid,
to a gas because we're giving it a lot of energy,
it's happening really, really fast and we're
skipping that liquid all together.
So those are some types of reactions that we like to
call physical reactions.
In chemistry we study physical reactions, but we
also study chemical reactions.
♪♪
In chemical reactions you can kind of
think of like a math problem.
You have these ingredients that go together, so think
about the number one, and the number two, and when
you add them together you get the number three.
So we have these ingredients that go
together to make something new and that is what a
chemical reaction is.
So today we're going to look at a couple of
chemical reactions and some safety tips to think
about if you do decide to do some kitchen chemistry
experiments at home.
This first one uses a solid, this little white
powder here called baking soda.
And even though it doesn't look very solid to our
eyes, it's solid because each of those little
grains of powder are solid themselves.
So solids don't even have to be big, they can be
really, really tiny too.
Now, I've gone ahead and put my baking soda in this
super scientific balloon.
And in this balloon we have just that solid and a
little bit of air from the air around us.
Then in my flask I have a chemical that you're
probably familiar with called vinegar.
And vinegar, it's really stinky.
It looks like water, but it's not water.
And in order to do our experiment here I'm going
to give it a little bit of color, because color is
always fun.
So we're going to give it a little bit more color,
swirl it around, so now we just have blue vinegar.
I'm going to take my baking soda and control
the experiment by putting the balloon over the top
of the flask.
And then we're going to combine them together.
Now, scientists, one of the most important skills
they have is observation.
And they use all different types of their senses to
observe.
Sometimes they observe by what they hear, sometimes
they observe by what they see, sometimes they
observe by what they smell.
Remember that vinegar and how it was kind of smelly.
And then we can also observe, we don't often
want to do taste, but we can observe by touch or a
temperature change.
So I want you to be thinking about what you
could observe as I do this experiment.
Remember, we have a liquid, we have a solid
and what could we be making as we put those two
together?
Ready?
Here we go!
♪♪
So what do you notice?
What do you notice happening?
Do you see the fizzing and the bubbling?
You might not be able to hear it, but it definitely
is making a sound.
I can tell you that my container has gotten a
little bit colder.
And probably the biggest one that you've noticed
already is that my balloon has blown up.
And that is because when we added the vinegar and
the baking soda together, remember think of that as
a math problem, we made something new.
We made carbon dioxide.
Do you remember carbon dioxide from earlier, that
CO2, that one carbon atom and those two oxygen
atoms?
That is the product when you combine vinegar and
baking soda together.
So we did what is called a three state reaction.
Remember, we had that solid, that baking soda
powder.
We had the liquid, the vinegar.
And then we made a gas, that carbon dioxide.
(laughs)
So, I have one more experiment to do that
is one of my favorites.
But before we do that I want to talk a little bit
about safety.
One of the things about chemistry and matter is
often things look the same but are different.
And so observation isn't always something we can
rely on only by our eyes.
So in this flask this clear liquid is water.
In this flask this clear liquid is vinegar.
Would you want to drink vinegar straight?
No.
It wouldn’t taste very good.
And in this flask, even though it looks the same,
this is a completely different chemical called
hydrogen peroxide.
And this is something that doctors use and nurses use
at the doctor's office.
It helps clean up things and keep them nice and
healthy.
But the difference between water and hydrogen
peroxide is you definitely don't want to drink
hydrogen peroxide, just like you don't want to
drink vinegar.
So we have to be really, really careful in
understanding what we're putting together before
hand and knowing that it's going to have a safe
result afterwards.
♪♪
So, in our final experiment we are going to
use that hydrogen peroxide.
Now, hydrogen peroxide is pretty close to water on a
molecular level, or all those little molecules.
So that molecule is made up of two hydrogen and two
oxygen, it has an extra oxygen.
And over time that hydrogen and that oxygen
break down apart from each other into a liquid that
we're familiar with, that water, that H2O and that
gas, oxygen, that we're familiar with, which we
need to breathe on a daily basis.
So here in my flask I have that hydrogen peroxide.
And remember, I'm wearing gloves to protect my
hands.
And in order to make our experiment just a little
bit more fun I'm going to add a whole bunch of food
coloring here.
And we're going to swirl it around and get it
really well mixed up.
So we have our hydrogen peroxide in here.
Now, in order for us to see what is happening a
little bit better I'm going to add some liquid
dish soap and I want you to think about what
happens when you put a gas in liquid dish soap?
Maybe you've blown bubbles before?
And we're going to stir that together and mix that
up really well again.
Now, that chemical reaction of breaking down
the hydrogen peroxide into water and oxygen usually
takes a long time.
But scientists have this special tool called a
catalyst which allows us to speed up reactions.
So we want to be able to see this move faster, we
want to see that happen faster.
In this case, this is a very common catalyst, I
have yeast that I've been growing here for just a
little bit.
And a catalyst, this yeast catalyst allows that
reaction to just happen on top of it.
It's kind of like the molecules are having a
dance and breaking apart but it doesn't actually
change the yeast.
So we are going to see that chemical reaction of
that hydrogen peroxide breaking down, making new
products as we go.
Are you ready?
Here we go!
In three, two, one, and sometimes reactions take a
little bit of time to get going.
And there we go.
You can see and observe with your eyes, we have
all this wonderful foam coming out.
So it's just really dense bubbles, lots and lots of
bubbles together that are filled up with that oxygen
gas that is coming from the breaking down of the
carbon dioxide to turn into that water and the
gas.
And we like to call this elephant toothpaste
because it makes a lot of it and you can imagine an
elephant brushing its teeth.
So, just to recap today we talked a lot about matter
and how matter is everything around us.
It comes in different states and shapes, solids,
liquids and gases.
And there's different types of reactions that we
experience around us when we're doing chemistry,
those physical reactions where we have matter that
is just changing shape, and those chemical
reactions where we're making something
completely new.
I want you to remember that to do your science
experiments safely you can go to sciowa.org to Go
Beyond with SCI and do kitchen chemistry
experiments at home.
Thanks a bunch and it's been great learning with
you today.
♪♪
Experiments like those make chemistry so
much easier to understand, and pretty exciting too.
That was amazing, Allison!
Thank you everyone for going beyond with Iowa PBS
and the Science Center of Iowa.
And always remember to ask questions and wonder.
That's what science is all about.
♪♪