All language subtitles for The Modern Alchemist 2of3 Water The Fountain of Youth_Subtitles01.ENG

Early alchemists
wrote of a Fountain of Youth,

and for centuries kings
and explorers searched

for this legendary spring
that would restore the youth

to anyone who drank from it.

Does such a place even exist?

And, if it does,
what incredible elements

might we find in its waters?

Join us in the search
for the Fountain of Youth.

APPLAUSE

Many people searched
for the Fountain of Youth,

but one of the most famous was
the 16th Century Spanish explorer

Juan Ponce de Leon,
who spent his life

trying to hang onto his good looks.

And legend has it that he found
the Fountain in Florida.

Local people claimed this miraculous
spring could even restore

frail old men to perfect health

and, incredibly,
the spring is still there.

On the screen now we
can see the workers

filling bottles from
this Fountain of Youth

And they've sent us a sample
by airmail.

Here we have our Fountain of Youth.
I can't wait.

Right, let's have a look.

"It's on the shelf." OK.

Right, so here it is.
They've put it over here.

So here is the Fountain of Youth.

It really has come all
the way from Florida

which is quite exciting,
but we need somebody to try it.

Do I have a volunteer?
Some hands went up...

I'm afraid I can't give it
to anyone down the front.

You're far too young already.

If I gave you this,
who knows what might happen.

We need somebody
slightly more mature,

slightly more advanced in years.

I'm looking at the top, actually,
and...

Oh, yes, there's a chap
right on the end.

What's your name, please? Tim.

Tim. And you'd like to try
some of the Fountain of Youth?

I'll give it a go.
You'll give it a go.

That's very good of you.

I think we've arranged for some to
be brought up to you.

LAUGHTER

Goodness me. Is it safe?

DR WOTHERS LAUGHS

Well...

Don't drink it all!
Save some for later!

So, are you feeling any younger?
Not yet.

Not yet? No wrinkles lost yet?
Don't know. Don't know. OK.

We'll come back to you
later and see how it is going,

but you were very good.
You must be a chemistry teacher.

You did ask, "Is it safe to drink?"

You shouldn't be drinking in the
chemistry lab, so well done there.

Thank you very much.

A round of applause for Tim
for trying our water.

APPLAUSE

This year's Royal Institution
Christmas Lectures

are all about the elements.

My name is Dr Peter Wothers,

and I'm a Fellow of The Royal
Society of Chemistry.

The ancient Greeks thought

there were just four elements
that made up everything around them.

These are the elements earth,
air, fire and water.

Last time we looked at
the elements in the air,

and tonight we're going to be
looking at the elements in a glass
of water,

in fact, the water that Tim
has just drunk, to be precise.

To help me, we're going to
be using our periodic table.

Periodic table. Look at that.
Excellent.

Very good, everyone's here.
Marvellous.

We now know, of course, that we've
got over 100 different elements.

Together, we're going to see what
elements we can find in our water

and maybe we're going to find
something quite miraculous

in our glass of water,
the water that Tim's just drunk.

OK. Right, I need to put on
my coat, ready for action now.

So, thank you, periodic table.

Excellent. Oh, you're so
well-trained, really! Excellent.

That's perfect, look at that.

So, our periodic table, we saw that
there's over 100 elements.

And yet, water, of course, isn't one
of these elements. We know this now.

But this was only first realised
about 200 years ago, just over.

So, why was that? Well, partly
because nobody had ever done this.

BOOMING EXPLOSION

ALL GASP AND GIGGLE

Well!

That seemed to bring the house down!

APPLAUSE

That was certainly rather dramatic!

But what we actually did there
is just make some water.

The balloon
was filled with hydrogen...

which, of course,
when we light it...

combines with the oxygen
from the air...

to form water.

OK. Now, that was rather violent,

and we couldn't see
any of the water that we made

because as soon as it was made, all
that energy that was released there

vaporised it and disbursed all the
droplets into the lecture theatre.

But we can do this
in a more controlled way,

so we can actually see
some of the water being formed.

And, well, this is the apparatus
that we're just bringing on now.

OK, so...

We're going to combine
our hydrogen and oxygen

in this carefully designed
apparatus.

And we're passing pure oxygen
through this,

and Mark is just going to pass me
a tube with some hydrogen.

And let's just light that.
Ah, beautiful.

It's very difficult to see
this flame sometimes

because hydrogen burns with
more or less a colourless flame.

I think there's a few impurities
in the glass there,

but you can see it's definitely
lit, it's definitely going.

I'm just going to insert this
into the apparatus.

I hope I don't catch fire
to our little things there!

There we are, look at that,
beautiful, right.

So, just insert this.

In fact, as it's going in,
the flame gets much hotter,

because this is an oxygen-rich
environment in this apparatus.

And it's just beginning to vaporise
some of the glass.

And this yellow colour
that you see now

is excited sodium atoms
from the glass.

But I'd like everyone to keep an eye
on this during the reaction.

This is like our little
Olympic flame.

If this goes out, please let me know
during the course of the reaction,

I'm trying to generate enough water
to maybe taste it later.

We'll have to see,
we're using very pure gases here.

The important thing that we can see
is that we've got our flame,

it's clearly very hot,
but we are generating water.

You can see that this is misting up
now at the top here,

and we're beginning to get some
water and it's dribbling down here.

So this is actually showing us that
water is not an element after all.

It's made up of these two gases,
hydrogen and oxygen.

This, as we are forming these bonds
here, is releasing a lot of energy.

This is, as we're making new bonds

between hydrogen atoms
and oxygen atoms,

forming our droplets of water,
that are beginning to collect now.

But I'd like to show you another
reaction that clearly generates

a lot of energy, a lot of heat
as molecules are coming together,

as bonds are being formed,
and this one is quite miraculous.

This is one of my
favourite reactions,

because it really does
look like magic.

What we've got here is
a tube just of cold water.

Everyone knows what temperature
water freezes at, don't we?

What temperature does it freeze at?

ALL: Zero.
Zero, exactly.

So here it's coming, this is
a test tube full of cold water.

Thank you very much.

What temperature is this water at?
Minus three.

Minus three, this one.
So this is actually at minus three.

And yet, of course, we know that
water SHOULD be ice at minus three,

and yet it isn't. OK?

Now, watch what happens when I add
just a tiny little crystal of ice.

This is now freezing. OK?

So you can see that this water
is turning into ice.

In fact, the ice is
all the way down to here now.

So we know that water should be
ice at minus three degrees,

and it is now becoming ice
at minus three degrees. OK?

In fact, let me see if I can
actually turn this upside down.

Can I do that?
There's a little bit dribbling out,

but there we are,
it is in fact solid ice there.

That's pretty impressive, I think.
Let's hand that out, thank you.

Now... How can we...?

So, how can we do this?

We need to be very careful, it's
like trying to balance this pen.

I was trying it with a pencil
earlier and it didn't work.

I can balance a pen
on its end there.

If we're careful, we can do this,

but just give it a small jolt
and it falls over.

Now, we can really cool down
our water very slowly,

very carefully, we can get it
to those temperatures

if it's very, very slowly cooled,
really pure water.

But just give it a small jolt,

it starts off this process
of being how it should be.

The question now is, what do you
think happens to the temperature?

Do you think it stays the same?

Do you think it gets hotter,
or do you think it gets colder?

We're going to have a vote.
So who thinks it stays the same?

OK, quite a few. Who thinks
it gets colder when freezes?

Quite a few of you.
And who thinks it gets hotter?

It's a bit of a mix, I think.
Let's see what happens.

I need to take this
very, very carefully.

And here we can see that the
temperature is indeed at -3.7.

This is really pretty good,

in this huge tube here.

I might need some ice,
but I'm just going to give this...

Look at that,
just moving it has set this off.

Look what's happening to the
temperature. It has shot up.

It was at -3.7, it's now just...
Well, it's actually,

this top part is now above zero.
And again, it's freezing.

This is because
as the water molecules...

They were moving around
in the liquid,

but as they're locked into place
in the ice

we're forming bonds
between the water molecules

and the temperature goes up.

That's really beautifully done,
it's incredibly difficult to do,

and I think we should thank Fiona
for preparing this all day.

Thank you, Fiona.
OK, thank you.

So the formation of bonds
releases energy.

This is a very important thing.

Now, actually,
we can show this in another way.

If you look under your seats,
you'll find a little hand warmer.

Now, for those of you, of course,
watching at home, I'm afraid,

if you look under your seats, you
probably won't find a hand warmer

unless you remembered
to put it there earlier,

in which case, well done!

OK, looks like people are finding
their hand warmers.

Your hand warmer contains a solution

and it has salts dissolved in this.

But actually, again,
it's an unstable situation.

There are more salts dissolved
than there should be.

So if we just give this a click,
if you haven't done this already,

you just click the little bit
of metal in the corner.

That's it, I can hear
lots of clicking going on.

That's just starting this
reaction now.

EXCITED CHATTER

And it's resorted to
exactly how it should be.

We are forming bonds,
the salts are precipitating out,

and as they're forming bonds,
forming the solid here,

formation of bonds gives out
energy and that's what you can feel.

That's what's warming up your hands
now, which is rather nice. OK.

So the formation of bonds
gives out energy.

And that's what's taking place
with our little flame here,

our Olympic flame.

I think we might just turn up
the hydrogen a bit, lovely.

So, here we are forming bonds
between hydrogen and oxygen

and that's releasing energy.

And this is a really beautiful
reaction here,

because the only by-product
of this is water.

You may know, of course, when
you burn petrol and other fuels,

you get carbon dioxide,
this is a greenhouse gas.

The only by-product here is water

and there's a lot of energy
being released.

So maybe this could be an answer to
the energy problems of the future.

Well, have a look at this.

APPLAUSE

This is Nathan Chang from
Valeswood Fuel Cells Ltd.

Nathan, can you tell us,
what is this thing?

It looks like a normal road bike.
You can put it on the road, can you?

It's a road legal scooter,

but we put the fuel cell
and hydrogen on there.

This is lanthanum nickel hydride?

That's a nickel metal-based hydride.

And it's absorbing the hydrogen...
Like a sponge.

Like a sponge,
and gradually releasing it.

It's combining with the oxygen
from the air.

That's giving you the energy
to power this bike.

Yeah, that fuel cell generates
electricity to power

the motor and power the vehicle.
OK, this is great.

So you've just driven
all the way through the RI.

Haven't you polluted everywhere,

is there oil dripping
out of everything now?

The only emission is water vapour.
It's just water vapour.

And the hydrogen comes from water.

The hydrogen itself
comes from the water?

So you convert water to hydrogen,

the fuel cell converts
hydrogen to water again.

So why don't we see more vehicles
like this now?

Why don't we see more
hydrogen vehicles? Yeah.

The hydrogen is still very expensive.

And, also, you have problems to store
enough hydrogen for a bigger vehicle.

So you'd have to change your tank,
would you,

if you wanted to get back
to Birmingham?

You'd need a bigger tank.
A slightly bigger tank.

That tank can power this vehicle
for 70 miles.

70 miles, oh, pretty good then.

So, if we could get
a better source of hydrogen,

it would be cheaper,
then we'd see more vehicles. Yeah.

Because it's non-polluting,
it only produces water, yes? Yeah.

Give Nathan a big round of applause,
thank you very much coming in.

APPLAUSE

So we've got
a bit of a challenge here.

I mean, hydrogen could be
the ideal fuel of the future,

but the problem is,
how do we get it in the first place?

And one way that we can get it
would be to break up the water.

In fact, Nathan said that
the hydrogen that they're using

does come from splitting up water.

But we can see that when hydrogen
and oxygen combine to form water,

this gives out a lot of energy.
If we want to split up our water

to generate hydrogen and oxygen,
we need to put a lot of energy in.

We can show this, this is another
general thing of chemistry,

that if we want to break bonds,

we need to put energy
into the system,

and we're going to show this
first of all

by looking at interactions
between water molecules.

I'd like some volunteers
from the audience.

The back row, actually. That's it.

Give them all a round of applause.
APPLAUSE

In this space, lovely.

Hold up your balloons
so everyone can see. That's it.

Now, you're water molecules, OK?

And at the moment
you're bonded together

to form the rigid structure of ice.

So, of course, you're going to be
wiggling around, gently vibrating.

This is what ice looks like.

But if we give them more energy,
we can break some of these bonds

that hold the water molecules
together, and we get liquid.

Now you can start moving around.
Just have a little walk.

This is our liquid.
In fact, on the screen now,

we can see this is
a very complicated calculation

carried out at the University
of Cambridge from scratch.

This shows what happens when
liquid water molecules get together.

They're jiggling around,

but they are sort of held
more or less in place

with these dotted lines
that you see there.

These are bonds
called hydrogen bonds.

This is where the oxygen
of one water molecule

is slightly negatively charged,
and it sticks

to the slightly positively charged
hydrogen of the other.

Keep walking around.

But what happens
if we give you even MORE energy?

They start separating,

and we can get them
to fly out into the audience here.

This is where we're making steam,
all right?

LAUGHTER
So lots more energy,

the water molecules are separated,
and we've got steam.

So thank you very much,
water molecules.

Please return to your seats.

APPLAUSE

So, all we've managed
to achieve so far, then,

is pulling the water molecules apart
from each other to generate steam.

But this raises
a very interesting question -

how much more space
does the steam now take up,

compared to the water?

So, in other words,
if I took one millilitre of water,

how many millilitres of steam
would I be able to get?

This piece of apparatus here
is designed to try and show us

how much steam we can get
from one millilitre of water.

And I need a volunteer for this one,
please. Er...

yes, actually, in the white.

Would you like to come down
to the front, please?

APPLAUSE

OK. And your name is? Connor.
Connor, OK, great.

Do you know how many
millilitres of steam

we're going to
get from 1ml of water?

Have a guess.
You've got a scale here.

You're going to be
looking at this scale.

It goes from zero up to 100ml.
How many do you think?

50. 50 ml.

In the middle, OK.
Who thinks more than 50?

Who thinks less than 50?

More than 50?

Yes? 100.

100. Any advances on 100?

Yes? 150.
Well, if it goes past 100...

150 is going to be past the dial.
I want you to watch the dial.

I'm going to squirt
the water in this end.

Here's my syringe. So this is
going to be 1ml of water.

I'm hoping that this
is all nice and hot.

So 1ml is not a lot.

If you see, that's just 1ml there.
and you think 50, don't you?

And we've got all sorts
of different guesses here.

So, right, I'm just going to turn
this tap and put this in,

and I hope, fingers crossed,
I squirt that in,

close the tap, and there we are.

Watch the thing. Let's see
how far it's going to go...

Keep going. 50...
oh, it's gone past your 50.

Still going. It's gone past 75.

Can we turn this on
actually? Is that possible?

To get this back up to temperature?
MACHINE WHIRS

Ah, brilliant!
Yeah, I can see it boiling now.

So we're trying to get some heat
back into this thing.

How far have we gone so far? 225.

Sorry? How many? 225.

225. Who said 225?

Oh, well done!

Well, we've gone past that now!
LAUGHTER

Right, OK, it's still going.
Got quite a lot of...

look down this end, actually.

Yeah, you can see
the water in there.

Yeah, still quite a lot.
Oh, you've missed the dial!

How's he doing? What's that?

300. 300, OK. Good, keep going.

Still water there. It's still
going, then. We're up to...

What are we up to? 450.

450, OK. Not quite hot enough.

It's so difficult to do this.
It needs to be SO hot.

Where are we up to now? 650.

650? We're still going.

There's still quite a bit
of water there.

This is just our 1ml.

OK. And this is now...
Where are we up to?

900. 900.

So quite a few people said...oh,
is that 1,000?

Yeah. That's 1,000, OK.

Now, it's still expanding.

We'll keep counting here.

But this is actually really quite
important, this expansion here.

It's THIS expansion that drove,
quite literally,

the Industrial Revolution.

It was the power here,
as water is turned into steam,

driving pistons,
driving our machinery.

How are we up to so far?

1,375. 1,375. Very precise!

You're a keen scientist, I can tell!

Physicist. Physicist! Ah!

Almost as good as a chemist!
LAUGHTER

Anyway, how are we doing now?
This is coming up to... 1,650.

1,650. OK, we're going to
have to stop this now.

There's a tiny bit there, but
this is going to go to over 2,000ml.

So, you're a physicist,
and you said, what was it? 50ml?!

Well, anyway, thank you very much.

Give him a big round of applause
for keeping track. Thank you.

APPLAUSE

So, we've converted
our water into steam,

and we need to put quite
a lot of energy in to do that,

but we still haven't
actually made our hydrogen.

This is what we were trying to do.

To do that, to actually
split apart the water molecules,

we need to put
even more energy into them.

And, we're going to show this now
with this apparatus.

So we've got some water
in the tubes here,

and I'm just going to plug this in.

So this is connected to here,

and this is a generator.

So if I hop on the bike,

I should be able to drive the little
generator at the back like this.

We can begin to see some bubbles.

It's quite hard work here,
trying to split up the water,

so I'm going to get somebody else
to do all the hard work, I think.

Actually, we need
quite a lot of hydrogen,

so I'd like you to welcome, please,

Paralympic gold medallist,
Mark Colbourne.

Thank you very much, Mark.

APPLAUSE AND CHEERING

Thank you for joining us.
Thank you very much.

LOUD APPLAUSE AND CHEERING

Some great warmth
from the audience here.

You've obviously
done a fantastic job.

Before you get onto this thing,
tell us a little bit about yourself.

You had an accident paragliding,
is that right?

I did, yes. May 2009.

So just over three
and half years ago.

I broke my back in a near fatal
paragliding crash in South Wales.

So I was very lucky to survive, yeah.

And clearly it's not affected
your legs too much,

since you can cycle so well!

Yes, I've been left with
lower leg paralysis.

So both my feet don't work, so I have
to wear special ankle supports.

No hamstrings firing, no bum muscles
firing, so it's all quads.

There's pretty big quads there,
so that's pretty good!

Now, this is what
I'd like to see. Yes!

Being a modern alchemist, this is
some gold, is it? Some real gold?

Yes, what you have here is my
very own Paralympic gold medal.

That's fantastic.

APPLAUSE AND CHEERING

This certainly feels pretty heavy.

Is this solid gold?

No, it's actually
390g of solid silver,

and then you have 22g of gold

obviously coated
around the outside,

and, proudly, actually made
in Llantrisant, in South Wales.

Oh, that's fantastic. Really good.

Nice to see a bit of gold
in the studio, as well.

I think we've got a picture of you
here, just crossing the line.

How did it feel crossing the line?
Just euphoric.

It was almost like Christmas
and birthdays rolled into one.

And you got one of these, as well.
Fantastic. Very much so.

But have you ever split up
any water molecules before?

That's the real question.
No, not in this sense!

Obviously, lots of sweat
when I'm training.

I think you need to give it a go.

If you'd like to hop on.
I'll look after this for you.

OK, wonderful.
Make sure he doesn't run away, OK?

LAUGHTER

Because I won't be able to catch him!

Yes, so, now then,
Mark's on this bike here.

All his power is going to go into
driving this little generator here,

and this really is just connected

to the water
we've got in these tubes.

OK, take it away then. That's great.

So we've got two electrodes here.

On the negative electrode,

this is where the
hydrogen atoms are collecting.

So, remember, the hydrogen
in the water is slightly positive,

the negative electrode
is giving them electrons,

forming hydrogen atoms,
and forming hydrogen molecules.

On the positive electrode,
the oxygen atoms,

which are slightly
negative in the water,

are having those
extra electrons ripped away

to form oxygen atoms and,
eventually, oxygen molecules.

But the interesting thing here,
as Mark's pedalling away...

Go on, faster!

The interesting thing is
that we can clearly see

that we're getting twice as much
hydrogen gas

as we are getting oxygen gas.

So this clearly shows, then,

that water is made up of
twice as much hydrogen as oxygen.

Oh, I think you've broken it!
Go slower!

Has it gone again? Sorry!

Pretty tiring, isn't it?
Don't you think?

Pretty tough.
Yeah, thank you very much.

I think a big round of applause
there for Mark.

APPLAUSE AND CHEERING

Perhaps...can I offer you
a drink afterwards?

Do you need a drop of water
after that? Yes, definitely.

Lots of water. Would you want this?

This is our Fountain of Youth.

In fact, we've got
a guinea pig trying this.

Tim, how's it going?

How's your Fountain of Youth?
Just the same.

Don't feel any different at all.
No wrinkles gone yet?

No, still there!
OK, we'll come back.

We'll give it a chance later.
But, anyway, thank you very much.

I'll give that one to you.
Thank you for coming.

Thank you. Cheers.

APPLAUSE AND CHEERING

So, we've seen, then,
that we need to put energy in

to split up our water.

And a lot of energy is needed there,

and I don't think that
using Olympic cyclists...

Even Britain doesn't have enough
Olympic gold medal cyclists

to power all the vehicles
in the future using hydrogen.

But there is another
way of doing this.

Our plants here use the energy
from sunlight to split up water.

They spit out oxygen
during the daytime, of course,

but they're using the hydrogen

to build up the molecules
they're made from.

So maybe we can learn from nature.

Now, Professor Akihiko Kudo
from the Tokyo University of Science

has worked on a catalyst here.

This is really quite remarkable
stuff. This is quite cutting edge.

This is a catalyst that can use

the energy of light
to split up water.

And the catalyst is made of...

Well, actually, if we can just have
our periodic tables up for a moment.

Very good, periodic tables!

OK, this catalyst is made up
of the element sodium.

Sodium, give us a little wave!

There we are. Very good, sodium.

OK, can you see sodium there?

And we've got tantalum, right
in the centre. Very good, tantalum.

And oxygen up there.
So this is sodium tantalate,

and it's doped with lanthanum.
Where's lanthanum?

There's lanthanum. Very good.

Give us a little wave
at the top there.

So this is the catalyst
that he's developed,

and this will convert
the energy from light

and use this energy
to split up water.

So, at ease, periodic tables!

Back down, thank you very much.

OK, so are we ready? Yep.

OK, now, we're just going to
put this on, then.

OK, now, so this is the catalyst,

sodium tantalate
doped with lanthanum,

and we're shining UV light on this,

and, yes, I can see some bubbles.

There are some bubbles in
the upper part of the chamber there.

If we just move up,
we can see some. There we are.

This is bubbles forming. So,
as I say, this is quite remarkable.

This is using light energy
to catalytically split up,

so this is not changing
the catalyst,

but it's splitting up water
into hydrogen gas and oxygen gas.

So we can see these bubbles here.

Now, unfortunately,
the slight snag with this one

is that it's using ultraviolet light
and not just visible light.

The plants, of course,
use visible light.

But scientists all round the world

are trying to work on
developing a catalyst

that will work very efficiently
with visible light instead.

And if you can do that...

Well, maybe somebody
from the audience

will be the scientist
that actually finds a catalyst

that will work with visible light.

And if you can do that,
you're going to be very rich,

and you will help to solve
the world's energy problems.

Right, so, I think it's time
that we actually checked the water,

after all this time making it.

So we had to take
a lot of precautions here,

to ensure that
this really is extra pure.

This is something
you should NEVER normally do

during any science experiment.

You shouldn't drink
the products of the reaction.

But this apparatus has been
specially designed for this.

We've used extra pure oxygen,
medical oxygen,

we've used extra pure hydrogen here.

So I am actually going to just
try a few drops of this.

Actually, it doesn't taste too nice,
to be honest!

LAUGHTER

But it's basically just pure water.

And Tim was using
the Fountain of Youth water.

If we look on the bottle
of the Fountain of Youth water,

we see there are
other minerals dissolved in it.

This is, of course, because
water is a very good solvent -

things dissolve in it -

and, well, look at all the other
components in our water.

We've got, for instance,
there's a lot of calcium,

there's quite a lot
of calcium there.

There's quite a bit
of sodium in this, as well.

So, sodium, what's your symbol?

SODIUM: Na!

OK, and do you have Na idea
where this comes from?

Where does this symbol come from?

Any ideas? No? No? OK.

Well, I'm going to show you.

Hold the sign up, please,
so we can all see. That's it.

So, Na, where does this come from?

Well, actually, I have a book here.

Thank you. Now, in the book,

we can see that this is a chap...

This book is from 1557,

and this man here,
he's making piles of compound here,

and this is actually
sodium carbonate.

They called it natron or niter.
And this is...

He's taking Nile water here,
so this is water from the Nile,

and this is why it's called niter,
from the Nile water.

This corrupted into natron,

and this is the word that gives us
the symbol for sodium.

Na comes from the Latin
version of this, natrium.

But it was first discovered
in water.

OK, thank you.
So, periodic table, at ease.

Thank you.
Now, how was this detected?

Because we can't see
any of these substances in water,

because they're present
in such small quantities,

we have to use a chemist's technique
called spectroscopy.

And this looks at how energy
interacts with electrons in atoms.

Give them some energy, they move up,
and as they drop back down again,

they can give out this energy
as light.

And each element has its own unique,
characteristic, unique colours.

It has its own spectrum, like a
rainbow barcode for each element.

And we're going to show this now
with all these symbols here.

These are the symbols
from group 1 elements.

Can we have group 1 only, please?
That's it. Put them up.

Hydrogen, well, you are, of course,
a component of water.

You're not really IN water,
dissolved in it,

so you can put your card down.

Francium, I'm afraid
you're too radioactive,

so there's going to be
no francium in our water,

so you can put your card
down, as well.

But these other group 1 elements,
well, here they are here.

We've actually taken
some symbols here

and soaked each of these
symbols with salts.

With compounds
of the appropriate elements.

And watch what happens
when we light them.

APPLAUSE

We can certainly see that the sodium
and lithium are very different,

but these ones look rather similar.

But, actually, they're not.

If we were to look very closely

at the colours of light
coming down here,

if we split them up
using a spectroscope,

we would see they have
slightly different colours.

The exact frequencies
of light coming out

are unique to these elements.

Now these two elements,
caesium and rubidium,

were also first discovered in water.

And they were discovered
by Robert Bunsen.

This is Bunsen of
Bunsen burner fame, of course -

not to be confused with

Bunsen Honeydew from the Muppets,
shown here!

LAUGHTER

But Robert Bunsen took litres
of mineral water, evaporated this,

and he found these new elements
in the water using spectroscopy.

And, in fact, he named these
elements

from the appearance
of their spectra -

caesium from the sky blue
lines in its spectra,

and rubidium from two very distinct
red lines in its spectrum.

OK, so, how do we find
these elements, though?

They appear in compounds in water,
not as their elements.

All of you,
all you group 1 elements,

you're actually metals.

We certainly
don't find metals in water.

And that's because all of these
metals actually react with water.

And this is what
we're going to show you now.

So we have here a tank,

and I'm going to add a tiny little
piece of sodium to the tank.

Let's have this one.
A little piece of sodium.

A little tiny piece.
I'm going to drop it into the water.

There it is,
dancing around the surface.

So it's lighter than water,
floating on the top,

but it's actually
reacting with the water.

We can see it's reacted there.

It's giving out hydrogen gas.

The sodium is giving up
its electron to the water,

to the hydrogen in the water,
forming hydrogen gas, OK?

It's rather disappointing
to see that one, though.

There's not a lot there.

I think we need, actually, a bigger
tank, and a bigger piece of sodium.

So let's try this.

OK, this is certainly
a bigger piece of sodium.

Now, of course, when this reaction
is done at school,

the teacher is always instructed

to not use a piece
larger than the size of a pea.

And, well, I thought
I'd show you why.

So we've got a piece that IS a bit
larger than the size of a pea.

Now then, we're going to add this
piece of sodium, then, to the water.

Are you ready? And, step back.

So it's floating
on the surface there...

EXPLOSION
AUDIENCE GASPS

HE LAUGHS
There's certainly
quite a lot of smoke!

APPLAUSE AND CHEERING

Well, you can certainly see why

you shouldn't add a piece
larger than the size of a pea!

LAUGHTER
COUGHING

Oh, dear!
I've poisoned the audience!

It's chemistry!
COUGHING

Right, now...

But it's not just water that sodium
can give its electron to.

We can also...
It can give its electron to oxygen.

So here is a piece of sodium

and I'm just going to cut this now

and chop it right down the middle.

There we are.

So this is beautiful, silvery metal.

So this is what sodium
normally looks like.

But just as it's left here,
exposed to the air,

it's reacting with
the oxygen in the air.

It's actually giving up
its electron to oxygen.

OK, we can see it's changing.

It's actually got
a sort of white crust

developing over the surface.

But, actually, if we just have

our periodic table up
for the moment,

and I want to focus on
group 1 again.

So others, down. Just group 1 up.

So we have sodium here,

and the key thing here is this
outermost electron sodium has.

I think we have
a graphic to show this.

This is the atomic structure
of sodium.

We have one outermost
electron there.

This is the thing that's very
easily given in chemical reactions.

But as we come down the group,

you've all got this
one outermost electron,

but if we look at, say, caesium,
right at the bottom,

so here's caesium,
and has lots more electrons,

but, again, there's one
outermost electron,

and this is even more easily lost
than it is for sodium.

And, well, we have some here.

This is caesium in this vessel.

The problem was,
we need to store it under argon,

and we had a slight problem.

We sealed it up so well,
we can't get it out!

LAUGHTER

So, I think the simplest thing to do

is actually to hit it
with a hammer,

which is what I'm going to do.

HAMMERING
Oh, well, that did it!

This is such a reactive element

that is soon as it comes into
contact with the air...

in fact, if you have
the lights down,

you might be able to see
some of the sparks that are...

ooh, yes, look at this.

This is SO reactive
that as soon as...

Ooh, dear! Lots of sparks!

..as soon as it as it comes into
contact with the air, it's gone off.

It WAS a nice, shiny metal.
It was a sort of silvery colour.

Sometimes it has a slight
golden colour,

but when comes into contact
with air, it forms this black oxide.

So, the caesium
is incredibly reactive

and it's given its electron
to the oxygen.

But there are other things that can
take the electron away

from these group 1 elements,

and one of them
is contained in this, in bleach.

Does anyone know
what element is in this?

AUDIENCE MEMBER: Chlorine!

Chlorine! Where's chlorine?

Yes, you're in bleach.
This gives the bleach its colour.

You're a really poisonous,
nasty element, I'm afraid.

You were used in World War I
as a toxic gas.

Not very nice!

But you're very efficient, though,
at taking electrons from things.

OK, we're going to see some chlorine
in just a moment,

but before I show you that,
I want to show you something else.

This is a really,
really remarkable book.

This is from the archives
in the Royal Institution here.

And this was from a lecture

that was delivered exactly
200 years ago, in 1812.

And the lectures
were four lectures,

being part of a course on
the elements of chemical philosophy,

delivered by Sir Humphrey Davy
exactly 200 years ago.

Sir Humphrey Davy was
the first person to isolate,

among other elements,
sodium and potassium,

and he also named chlorine
over there.

And these lectures were written down
during the lecture course

by a young Michael Faraday,

who was sitting in the audience,
exactly where you are now.

Davy was so impressed
with these notes

that Faraday wrote up
of the lectures,

that he gave him a job.

He got a job here
at the Royal Institution

and became one of the world's
most famous scientists ever.

Now, I'm certainly no Humphrey Davy,

but who knows,
sitting in this audience

there may well be
the next Michael Faraday.

Now, this is what
I wanted to show you, though.

In this book, Experiments Belonging
To The Lecture On Chlorine,

it says, "Mr Davy exhibited
a specimen of chlorine gas.

"It was in a clean glass tube."

OK, now, we actually have that
original sample of chlorine gas.

Here it is. This is the one
that Davy exhibited back in 1812,

which is quite remarkable.

So chlorine gets its name,
Davy gave it its name,

from the Greek, "chloros"
meaning "green",

because of this
greeny colour that it has.

We even have a sample
of the original sodium,

and this is Davy's original sodium,

prepared here at
the Royal Institution.

This is the metal,
floating, protected in oil,

because, as we've seen,
it goes off in air very quickly.

So, we've got sodium
and we've got chlorine.

Well, what happens
when you mix the two?

Well, you get some sodium chloride.

Now, they would kill me if
I did this, of course, with these,

so I'm not going to use the original
samples of sodium and chlorine.

But we do have some
other samples here.

Here's our sodium,
here's our chlorine.

And you can see this beautiful
green colour now of the chlorine,

you can see the beautiful
silvery colour of the sodium.

We've taken all the air
out of this side,

because we know that sodium
reacts very violently with air,

so there's no air here.

I'm just going to pop my goggles on,
if I can do that one-handedly.

There we go. And I'm now going to
let the chlorine from this side

into this side,
and see what happens.

So let's have a look.

Look at that.
This is sodium meets chlorine,

and the silver mirror
has disappeared,

and we've got this white crust
forming all the way round here.

It's gone white,
looks like salt, and, well,

that's because what
we've made here is salt -

it's sodium chloride.

So the chlorine reacts
with the sodium,

the chlorine takes
the electron from the sodium,

to form white sodium chloride.

This is just the sort of thing
you would put on your chips.

The chlorine itself is poisonous.

It reacts by taking electrons
from your body and poisons you.

The sodium is poisonous.
It gives its electron to you.

But once they've reacted,

we've got sodium chloride
and you eat it.

OK, thank you very much.

APPLAUSE

But there are actually
different sorts of salt.

Sodium chloride is just one salt.
There are others.

And if we have
our halogens up for a moment...

OK, all of you are very good
at forming salts,

especially with group 1. Can we have
group 1 up, as well, please?

OK, any mixtures of you
would form salts.

Not only could we have
sodium chloride,

we could have potassium bromide,
potassium chloride, or so on.

In fact, all of you halogens...

Do you know what the name "halogen"
actually means? Does anyone know?

Does anyone know anywhere?

It means "salt-former".

So you're all really good
forming salts.

In fact, that's how, as a group,
you get your name.

So salts, though,
have very different properties

when they're dissolved in the water.

The water itself
is completely different.

Seawater is not the same
as normal water,

and, well, we have some seawater
here to show you.

Thank you very much, periodic
tables. If you go down for a moment.

So I was fortunate enough
to visit the Dead Sea.

In fact, this is me floating
in the Dead Sea up here.

LAUGHTER
So while I was floating,

I was thinking,
"Well, what would it be like?

"What sort of things could we get
to float on the Dead Sea?"

Well, I need a volunteer, actually,
to help out with this.

And we'll have somebody from...

Yes, yes. If you'd like
to come down. Lovely.

APPLAUSE
Thank you very much.

If you'd like to
face the front here.

What's your name, please? Katie.

Right, good. We need to put
some protective clothing when you,

so just come over here
and put on some protective clothing.

I've got a block of metal here.

Now, what do you think
to this block of metal?

If you just hold this.
What do you think?

It's really heavy.
It's really heavy, yes?

OK, really heavy.
What do you think? How heavy?

Quite heavy, yeah.

So this IS solid metal.
This is actually...

You're looking very good in those!
Very fetching!

We've got a step here,
which was a very good thing!

If you'd like to stand on this step.

OK, this is some salty water.
This is essentially seawater.

I'm going to put on
my gloves, as well.

You haven't held this yet.
If you just hold that.

Just stand there for a moment.

Right, what you think of that?
Quite heavy?

Yeah! Quite heavy, actually!

Yes, it is quite heavy.

Right, do you think it's going to
float in the Dead Sea,

or sink in the Dead Sea?

What you think? 50-50.

Float or sink? Ask the audience?
Float.

Ah, float, OK. Float in the
Dead Sea. Maybe. It's quite heavy.

Covering your bets there.

OK, it is quite heavy,
though, isn't it?

Let's see, shall we?
We're going to drop it in.

You take that side. That's it.

And you put that in the water.

Lower it in gently, you don't want
to splash it everywhere.

That's it. OK, very good.
And just let go.

And... Oh, no!

Aw! Well, it sinks.

It did sink, yes!
It sank pretty quickly.

It was quite heavy, wasn't it?

It did sink pretty quickly there.

I'll see if I can
fish it out for you.

I'll do this,
I've got longer gloves.

And...ooh, not that long!
LAUGHTER

Anyway, right,
out comes the magnesium here.

This is a block of pure magnesium.

It is actually quite heavy,
you're right!

OK, there we are. Now,
we've got some other water here.

So this one contains sodium salts,

but this one contains caesium salts.

And if we just have our group 1
up again for a moment.

Oh, very good! Very efficient!

Sodium right at the top there,

and as we go down,
we get to caesium.

And, so, caesium is actually
heavier than sodium.

And, now, how quickly do you think
this is going to sink in this one?

Er, maybe a bit longer.
Take a bit longer to sink?

Yep, OK, all right.
So shall we try this one?

I'm just going to
put this in the water.

Are you ready? Do you want to
hold it there, as well?

Just gently let go. And, ready?

After three. 1, 2, 3, go!

AUDIENCE GASPS

Ooh!

LAUGHTER

Watch out for your gloves!
LAUGHTER

No, so it's not
actually going to sink.

It actually floats in the water.
So I'll just fish that out,

and I think you should get
a big round of applause

for your help there.
APPLAUSE

Thank you.

We'll just take those off you.
That's it. Lovely stuff.

Thank you very much indeed.

Yes, the block of metal actually
floats in the caesium salts,

and that's because caesium itself
is a heavier atom than sodium is.

We can get other salts, though,
from the Dead Sea, for instance.

It's not just sodium chloride.
In fact, in the Dead Sea

it's quite rich in another salt.

If we have our halogens
back, please.

OK, we have bromine
in the Dead Sea, as well.

It's not as bromine itself,
not as the element. It's as bromide.

This is where it's taken
an electron from something

and formed a negative bromide ion.

So we'd get things like
potassium bromide, sodium bromide,

if we evaporated our Dead Sea water.

And, actually,
I can demonstrate this

with some of the Dead Sea water.

I've got some concentrated
Dead Sea water.

I brought this back
from the Dead Sea.

Just the sort of thing
you normally bring back, I suppose,

if you're a chemist!

Right, here we are.
Here's my Dead Sea water.

And I'm just going to add
some bleach to that.

Of course, the bleach
has chlorine atoms in it.

Watch what happens,
just give it a bit of a...

AUDIENCE GASPS

OK. This, the colour
that you now see...

And we haven't cheated in any way,

this really is just Dead Sea water
that I brought back.

We just concentrated it a bit
by removing some water.

This is just bleach.

The colour that
you see now is bromine.

So with our halogens,
we've got bromide here,

and I've just added some chlorine
that was in the bleach.

So what we have there, the bromide
reacts with the chlorine,

chlorine takes the electron
from bromide,

and forums bromine element
and leaves chloride ions.

But chlorine, look behind you.
Who's behind you?

Fluorine!

Fluorine, exactly!

No fluorine is even better
at taking electrons away,

and fluorine can take the electron
away from chloride.

OK, fluorine, in fact...

That's right, give us a little wave!

Fluorine, you are THE most
reactive non-metal

in the entire periodic table.

You will steal an electron
from every other element

in the entire periodic table,
with the slight exception

of the very inert noble gases
sitting next to you.

But everything else, you will
react with. Very, very violent.

Fluorine is probably
THE most reactive element

in the entire periodic table.

Certainly the most
reactive non-metal.

Even as a chemist,
I had never seen any fluorine,

and I thought, for these lectures,

it would be really nice to bring
some fluorine into the lectures

and I needed to find
a specialist to do this.

So, would you please welcome,
from the University of Leicester,

Professor Eric Hope,
a fluorine chemist.

APPLAUSE

Eric, thank you
for coming along.

So, Eric is a fluorine specialist.

Fluorine is incredibly reactive.

It reacts with just about
everything, doesn't it? Indeed.

So, the question everyone wants
to ask is, how do you store it?

Doesn't it react with
the container you put it in?

It does react with the container.

You can store it in
metal containers, stainless steel,

or we hold it in nickel
containers in Leicester.

And what happens is
the fluorine reacts

with a coating of the metal,

you get nickel difluoride,
a very few microns thick,

protects the rest
of the nickel metal,

and you get an impervious layer.

So it HAS reacted, and what it's
formed is pretty inert afterwards.

Indeed, yes.

But fluorine is incredibly
reactive and dangerous, isn't it?

If you control and handle it
under appropriate conditions,

then it is dangerous,
but it's not THAT dangerous.

It's very reactive, isn't it?
It'll react, as you said,

with virtually every element
in the periodic table.

When I contacted Eric, I thought,
fluorine, really reactive,

it would be very great if we could
bring some of this into the RI.

But one reaction that
I've always wanted to try

is the reaction between fluorine -

because, you know, it is one of
THE most reactive non-metals -

I thought I'd like to try
the reaction of fluorine

with THE most reactive metal
in the periodic table, caesium.

Yes, you are best electron-giver!
Very generous!

So this should be
a really violent reaction.

I thought, I'd love to see this!

What did you think of this,
when I said I wanted to try

the reaction of fluorine
with caesium?

I thought it was the most outlandish
thing I'd ever heard,

and it took me a good 24 hours
to think about whether or not

it was feasible or possible
to actually do.

OK. Yes, exactly, we did wonder
whether we could actually do this.

Shall we just have
the periodic table down?

We thought,
"How could we do this safely?"

And we did have a practice

just to make sure
we could do this safely.

In fact, the remarkable thing was,

as I say, I'm a chemist,
and I've never actually seen...

I hadn't seen fluorine before,
before I went up to Leicester,

and remarkably, well...
I've never seen caesium before!

Eric had never seen caesium!

So we thought we HAD to
get together, really!

So I thought I'd bring
my caesium along to Leicester,

and we did test things,

and we're going to try
and do this for you now.

I'm actually just going to
hold this in my hand.

Just holding this in my hand
actually just melts the caesium.

So the bond between the
caesium atoms here are so weak,

just holding it in my hand
melts this. There we are.

We've certainly got some caesium
at the bottom of this tube.

Right, we're going to try, then,

the reaction between
caesium and fluorine.

The caesium is protected
by this blanket of argon...

..which is heavier than air.

And we've seen that caesium
reacts with the air.

And I'm just going to
lower this on...

..like so, and push this down.

OK, and I think we're ready
to try, then.

Ah!

AUDIENCE GASPS
APPLAUSE

We have to just use a tiny,
tiny bit. It's in this tube here.

But it did react very,
very violently with the caesium,

to form caesium fluoride.

OK, well, I think we need to give
a big round of applause

to Professor Eric Hope.

APPLAUSE

So, once the caesium has reacted
with the fluorine,

again, the caesium
gives up its electron,

and it's no longer the reactive
caesium metal that we started with.

And, of course, the fluorine,
once it grabs the electron,

it's no longer the reactive
fluorine we started with.

We've got fluoride ion.

And actually, remarkably,
fluoride is something that, again,

you can find in every
glass of drinking water you have.

This is actually added
to our tap water

because it protects our teeth
and prevents decay.

Now, talking of preventing decay,

I think we need to see how our
Fountain of Youth volunteer got on,

and see how whether it
really has worked after all.

So, Tim, how's it doing?

Has it worked?
I feel a lot younger!

Tim, is that really you?!

Ah, I can see what they did there!

LAUGHTER AND APPLAUSE

Tim, do you feel
any different at all?

No different at all, I'm afraid.
Just the same age.

OK, so it really looks like
our Fountain of Youth water

perhaps isn't restoring
Tim's youth to him.

But, nonetheless, water does play
a very important role in our lives.

Without it, we'd all be dead.

And this is because water
actually enables

chemical reactions to take place,

both inside the cells in your body
and in other reactions.

And this is what we're going to
demonstrate now. I have...

We've placed some magnesium powder
and some silver nitrate.

Now, they are touching
each other at the moment.

They're mixed up very intimately,
but not quite intimately enough.

What they need is to get
into really close contact,

and we do that
by adding a drop of water.

OK, now, they've given me
a glass of water and a pipette,

but I think I'm going to need the
slightly longer pipette, please.

This is quite a violent...

Thank you, that's a better one.
Right, now...

I'm going to take
the lid off of this.

It's sitting here
quite happily the moment,

nothing is taking place,

until we add a drop of water.

OK, I'm adding it now.

AUDIENCE GASPS

APPLAUSE

So this is an incredibly
violent reaction that takes place,

but it didn't take place
until we added the water.

So, maybe this gives us a method
for slowing reactions down,

if we remove the water.

Well, I think, actually,
it's getting time for my dinner,

and they've brought on some bananas!

Great! And these bananas
have seen better days.

Now, these bananas, I know,
are two weeks old, actually.

They've been sort of...eurgh!

AUDIENCE GROANS

It's actually a banana...

AUDIENCE GROANS LOUDLY

It's seen better days, I think.

But this banana...

..this banana, this one
was two weeks old.

This banana here is
actually six YEARS old.

AUDIENCE GROANS
Yeah, if I was going to eat one,

I know which one I'd rather have!

Now, why has this one
lasted so long?

Actually, what do you think?
Have a look at this.

What do you think?
What does it feel like?

Scaly. Scaly? Uh-huh.

What do you think?
What do you think it feels like?

Quite hard. Quite hard, yes.

It IS quite hard.

And this is because we've removed
all the water from this banana.

But this has actually preserved it.

It's stopped the reactions
taking place,

the normal reactions
where things go bad,

reactions taking place in the cells.

If we remove the water,
they can't happen.

And, well, maybe this could be
a way of preserving our good looks,

if we just remove the water?

Well, you could, and this is what
you might look like.

LAUGHTER
Well, this chap
might not look too good,

but he is 800 years old,
which is quite remarkable!

And the reason he's survived
looking like this

is because all the water
was removed when he died.

He died in the north coast of Peru.

It's very dry there,
and removing the water

has actually preserved
the cells of his body.

So maybe, then, this does give us
a clue to eternal life -

Remove the water and you can live
a long time -

well, looking like that -

but, of course, we need water
for our reactions to take place,

and so, well, I certainly know
which one I'm going to choose.

I think I'm going to stick to

keeping drinking the water
and staying alive.

Mmm! Freshly synthesised water,
delicious!

And I think, actually,
it's time for you to all have some

freshly synthesised water, as well.

So you may have noticed that
all around the lecture theatre

here is this very long tube.

This is over
half a kilometre of tubing,

filled with hydrogen and oxygen in
the right proportions to make water.

So we're going to synthesise
some water now.

So I need the end of the tubes,
please. OK, here they come.

Excellent. Thank you very much.

APPLAUSE

OK, now, the ends have some corks in

and we don't want to fire these
into our audience,

so we're going to fire them
into this bucket of water.

AUDIENCE: Aw!
HE LAUGHS

No, don't say "Aw!" - you wouldn't
want this! I can assure you!

Right, OK. But before
I do this, though,

before we do this final thing here,

I hope you don't feel
too disappointed

that we haven't found
the secret to eternal youth.

But we have discovered
a whole host of exciting elements

in that one glass of water.

Some of these elements
were deadly toxic

and others were explosive metals.

In the next lecture,
we're going to find out

how chemists are trying to extract
exciting elements from the Earth.

These are elements that have been

trapped in rocks
for billions of years.

And we'll also try to solve

the biggest alchemical
mystery of them all,

how to turn lead into gold.

But before we finish, though,

I think it's time for everyone to
get their freshly synthesised water.

So we'll have...

Yes, I need to move this from here!

OK, and we'll have a countdown
from three when you're ready.

So we're just going to aim these.

And if we have the lights down? OK.

So, you might want to be looking up,
rather than down at us.

OK, you look up at the pipe.

OK, so, three, two, one!

EXPLOSION
SCREAMS

HE LAUGHS
Thank you very much!

APPLAUSE AND CHEERING
Good night, thank you!

Subtitles by Red Bee Media Ltd