Mom always told you not to play with
your food, but that never stopped
our science guy Steve Spangler
from turning the kitchen table
into a mini science lab always
making a mess in today science
minute he shows us how to use
density to stack colored liquids
on top of each other and it is
easier than you might think.
Look at this five
different colors, their clear to blue
and you can actually watch this
layer them in a straw.
What's the secret to this density?
It's super super easy to do and kind
of a cool way to learn something about
density at the same time, all right?
So all of these liquids are not the same.
In fact, I'll show you how to prepare them.
We start here with five cups so
they're all going to have water,
and in fact the same amount of water.
So density is mass divided by volume,
so we're going to keep the same volume
in each one of these same volume.
But we're going to add something to each
one of these, not just food coloring,
but we're going to add table salt all right.
So there's going to be a different
concentration of table salt in each one,
so that's what density is really all about.
It's the amount of stuff,
so to speak, in a particular area.
So no salt in this one here.
That'll be the clear one.
Let's just put a teaspoon in here.
Let's do 2 teaspoons in this one here, right?
There's a lot. Three in this one?
Yeah, that's a lot.
You can see that we could dilute
those later on if we wanted to.
And finally, four in this 1/2.
There's a ton three,
and we're really gonna stir those.
We're gonna put food coloring each one
so they dissolve so you can see that
we have clear red output in yellow,
green and then blue.
Transfer all of that over here.
And that's exactly what we have so
we have no salt in this one here,
and we have 123.
4 teaspoons of salt in this one over here.
So now we're going to do that old
trick where you put your thumb over
the straw and you can trap the air and
then be able to pull it up, right?
You know what I'm talking about,
so you put it down like this.
Put your thumb over the top and
then lift up and you can pick up
some of the liquid, right?
Mom said.
Don't play with your food,
but now it's paying off.
So look,
I should be able to put
for example clear here.
So no salt at all and come over here
and let's see if I can let go.
You can layer it, see.
No problem at all now.
If you do it the opposite way though,
that's when you run into problems.
So if you start blue here and now,
we take it over to clear
and we put it in there.
We'll look at how it just all mixes.
It doesn't layer at all.
So if you didn't know the concentrations,
you could kind of try it this way.
Let's see, I think that that red is
going to be less dense than the green,
so we'll do our holiday colors right there
and slowly let it up and in there you got it.
There is your layer, so it's.
Easy to be able to do so when
you wanna do the whole thing.
It's just going to take a little bit
of patience ready so we dip it down.
We let go and we put it down into
the next one and just let
your thumb go. The air
pressure pushes it up, so that's
our next layer there. You
just kinda gotta guess how much
each one can go down the the
taller the glass, the easier it
is to do. Finally one more at the very top.
Let's see if I can get just a
little bit of blue. Got just a
little bit of blue there and there.
Or your liquid layers in the straw.
Now anything worth doing is worth overdoing,
so it's fun to do it in a straw.
It's great to do in a great big
huge cylinder like you see here,
and for that, well,
I just had to have a modified
funnel so I could slowly layer
each one of these in here and
to create this amazing layer.
It's something that you can do.
It's easy to do in,
understand something about density
at the same time I'm Steve
Spangler and that's your liquid
layer stacking science minute
made me want a popsicle. I was like that.
Playing a popsicle is a good
Roy G Biv to yes it was.
Yeah, and I thought was gonna
be messy. That wasn't me.