Lesson 2

1 2 3 Let’s begin at the beginning.
The first element is . . .
HYDROGEN! Hydrogen is in the upper left corner
of The Periodic Table of Elements. H stands for Hydrogen.
Can you find it in the table on slide 2?
4 Hydrogen is the simplest element.
Most of the ordinary matter in our
universe consists of hydrogen.
BUT NOT FOR LONG! The other 1/4
of the matter in the universe are all the other elements.

3/4 of the matter
in the universe
is hydrogen!
Remember: Every 20 minutes all the cells double.
One hour is 60 minutes, so there are 3 doublings in an hour.

Now suppose the cells continue to multiply for seven hours?
How many doublings would that be?
That would be 7 hours x 3 doublings/hour = 21 doublings.
If you multiply the number 2 times itself 21 times,
the number you get is above 2 million cells!
5 The Big Bang
is a theory
that explains
the origin of
the universe.

To fit
the scientific
data, it
predicts that
the universe
began as
a single point
13.8 billion
years ago.

From that
beginning
it has expanded
and stretched
to its current
size.

The
universe
continues
to expand!
Almost 14 billion years ago! Hydrogen was formed
shortly after the Big Bang.
6 Two of the outer giant planets
in our solar system
are mostly hydrogen.
Hydrogen:
the nuclear fuel of our Sun.
Uranus Neptune Jupiter is 90%
hydrogen.
These two, called ice giants, have about 80% hydrogen atmosphere, but they also have
an icy mantle and a core of rock and ice.
Saturn is 75% hydrogen. Hydrogen is the energy source for our Sun and
other stars.
7 There is a lot
of hydrogen
locked up in
water molecules
on the surface
of our own planet.
8 Water Molecules - H2O You probably know
that the formula
for water is
H2O.
H stands for hydrogen.
O stands for oxygen.

This formula tells you that every water molecule in our oceans, rivers, lakes and clouds is made up of
two hydrogen atoms and
one oxygen atom.
Water (H2O) has
two hydrogen atoms
linked to one oxygen atom.
Water Molecule (H2O)
9 Just as letters of the alphabet
are combined together to form words,
elements of the periodic table
are combined together to form molecules.

Two hydrogen atoms
combine with one oxygen atom
to form a molecule of water.
H2O
10 tray or
casserole dish
red and
black wire
connectors
2 test tubes
with graphite rods
Find these items around your home. Let’s split water into hydrogen and oxygen to make: Find these items
in your kit.
rocket fuel!
11 Pour a tablespoon
of salt into the tray.
Add water and stir. While keeping the tubes below
the surface of the water,
tilt the open end of each tube up
until all the air bubbles out of the tube.

There should be NO air left in the tubes.
Put the tubes
with the
graphite rods
into the tray.
3 2 1
12 Connect the red wire
to the positive terminal
of the 9 Volt battery.

Connect black wire to
the negative terminal.
Raise the other end
of one tube up and
connect the red wire
to one graphite rod.
This will be your
positive electrode.
Connect the black wire
to the other graphite rod.
This will be your
negative electrode.
WARNING! DO NOT LET THE Metal Teeth on the RED LEAD touch
the metal teeth on the black lead.
DON'T SHORT OUT THE BATTERY!
4 5 6
13 Watch as the bubbles form and
rise to the top of each tube.

If you don’t get bubbles, add more salt
and check your battery.

WAIT at least 15 minutes for the tube
collecting hydrogen to fill up with gas.
The hydrogen will collect in the tube with the negative electrode (black wire).
This black wire was connected to the negative terminal of the battery.
The oxygen will collect in the tube with the positive electrode (red wire).
Carefully disconnect the wire leads
without tipping the tubes.
8 7
14 You added electrical energy
in order to split water into hydrogen and oxygen.

Water is a very stable compound.
This is why water is so stable for cooking.
It will not catch fire.
You can think of water as already burned.

Hydrogen, on the other hand,
is extremely flammable.
Let’s POP the hydrogen gas!
15 Carefully lift the tube filled with hydrogen,
the one that was connected to the BLACK WIRE.

KEEP THE OPEN END OF 
THE TUBE POINTING DOWN!
Did you hear a popping sound? 1 2 If you turn the tube right side up,
the hydrogen is so light, it will float away immediately.
Have an ADULT light a match.

Bring it near the hydrogen
in the test tube.
CONGRATULATIONS!
YOU POPPED HYDROGEN!
16 Hydrogen is extremely flammable.
It makes an excellent fuel, so good in fact, that it was used in the space shuttle as ROCKET FUEL!
Water has been found on the Moon.
Why were scientists so excited about this possibility? ROCKET FUEL!
They hope to use frozen Moon water
to fuel return trips to Earth,
as well as to launch further explorations
of the solar system.
17 Hydrogen 18