Water Abundance and History
Name: William T.
I have both read and heard that we are dealing with the
same amount of water in the world that has always been here since the
world was formed. Is this true? If this is true, Why do we have free
hydrogen and free oxygen atoms? Why don't they bond into a water
molecule? What about the hoards of kids (of all ages) who have, by using
electric current, seperated the atoms of the water molecule and
subsequently demonstated to the neighborhood the volatile properties of
the hydrogen? Is there some saturation point within the relatively
closed eco-system of the earth that requires the recombination of those then
free oxygen atoms?
Apart from any liquid waste which might have been released into space by
astronauts and not returned to our atmosphere, I think your comment
regarding a stability in the amount of water, or its component atoms, is
Since the beginning of time there has been a water cycle in evaporation and
precipitation, and subsequently the capture of hydrogen and oxygen molecules
from water into simple and complex sugars of photosynthesis. You could
think of this as that perhaps an atom of oxygen once breathed by ancient
peoples might, with good likelihood, currently be present in your lungs.
That same atom might, however, also be present feet-deep in the wood of a
sequoia somewhere in California or riding along in the currently-hovering
space shuttle. The message here is that the earth is the great recycler,
that more or less the component atom count remains stable.
A chemist could detail the reasons free hydrogen and free oxygen may be
present without bonding...note that since the earth is comprised of
literally billions and billions of ongoing chemical reactions, it is
understandable that products of these reactions, viewed in a snapshot of
time, could be present in somewhat unstable states. In the absence of a
trigger (consider the Hindenburg) hydrogen and oxygen will not instantly mix
and form water....with the addition of a spark, however, water is formed
with a great release of energy.
For your question about the neighborhood demonstrations of electrolysis,
consider the volumes you are discussing as being like a drop in the ocean.
Those relatively miniscule volumes of gas indeed become mixed into the "air"
and become incorporated in everything from plant and animal tissue to the
dust on your tabletop. Unstable atoms do indeed react with other unstable
atoms to reach more-stable states. (Consider the production of oxone
resulting from lightning strikes and subsequent bonding of the freed oxygen
The message I am giving here should not be misinterpreted. No one should
consider the earth's environment as limitless...we have all discovered in
the recent past that wastes we thought would be diluted to safety in our
'limitless' environment have begun to accumulate within cities' air and
nearby city waste centers. The immense volumes and greater toxicity of some
of those materials, however, creates the difference in how effectively they
are diluted in the environment to levels of safety. Volumes of the gases
you mention, while present, are present usually shorter-term and in only
minor degrees in the air we breathe. Note, however, if every person in
every neighborhood suddenly gave an electrolysis demonstration, we could
indeed notice a pollution event. As a side issue, in fact, there is ongoing
discussion of levels of pollution resulting from poorly-running lawn care
equipment; used on a city-wide scale, these machines could adversely impact
air quality, again, because of the volumes and hazards of the gases
Thanks for using NEWTON!
No, it Is not true. It Is approximately true, but not strictly true.
Water can still enter the earth from icy meteors. (There is debate
currently on how rare these actually are.) Also, the fossil fuels of the
earth's crust contain hydrogen (bonded to carbon atoms), which creates water
when burned. Conversely, every day, the earth's green plants consume water
and carbon dioxide to make oxygen and sugars. In time, most plant tissues
will decompose back to water and carbon dioxide, so the water consumed will
eventually be re-formed, but that's not the same thing as saying that all
water molecules have been water molecules for the last 4.6 billion years.
Free hydrogen gas (H2, not hydrogen atoms) actually is light enough to
escape the atmosphere. So, some of the water electrolyzed by kids'
experiments is forever lost to the world.
Richard E. Barrans Jr., Ph.D.
PG Research Foundation, Darien, Illinois
Free hydrogen and oxygen atoms do not exist in any appreciable amounts in
earth's atmosphere -- in fact, they are quite rare. Gaseous hydrogen
(molecules, as opposed to free atoms) lack sufficient mass to be held by
earth's gravity. Like helium, hydrogen released into the atmosphere is lost to
space. Thus, we have insufficient concentrations of H2 and O2 reactants to
significant amounts of water in our atmosphere.
In addition, placing the gases together is not all that is required to make
them react. They must be nudged with "activation energy" to trigger their
reaction. As demonstrated by numerous science fair projects involving the
electrolytic dissociation of water, H2 and O2 when mixed in the correct
proportions can react explosively when initiated by a tiny spark.
When hydrogen and oxygen do react to form water, a great deal of energy is
released. In order for one to dissociate water into hydrogen and oxygen, that
same amount of energy must be expended to accomplish the dissociation. The
second law of thermodynamics tells us that in such a process, we can't even
break even. In other words, it would be hopelessly inefficient to make
electricity by conventional means and then to use that electricity to
electrolytically dissociate water into hydrogen and oxygen as a new fuel
source. We would "spend" more energy than we would gain.
Scientists are searching for a low energy pathway that can lead to the
dissociation of water into its elements. If they are successful, the world's
energy economy could be relatively pollution free when the hydrogen and oxygen
are combusted to form only water. Alas, there are no such activities that are
entirely pollution free. In the world of energy conversions, there is no free
Just as civilization used the horse (fueled by oats) and the tractor
gasoline) to accomplish work to difficult to be performed by hand, science is
seeking a way to harness other workers to do our bidding. The
of water assisted by certain kinds algae is an area being investigated. If we
can use sunlight and the assist of plants in place of fossil fuels to separate
water into its elements, we might be on our way to a hydrogen-based economy.
Search the Internet for information on hydrogen fuel cells. There is much out
there that you will find of interest.
Considering the Universe in its totality, hydrogen is by far the most
abundant element, with helium being second. Yet both of these elements in
their free state are present in our earthly environment in very small
amounts. So there is not much free hydrogen around.
Geologically speaking, the amount of water present on the globe may now be
pretty much constant; however, we cannot say with any certainty that this was
the case many millions of years ago during the earth's formative years.
Indeed the amount of "fresh water" is being consumed at an alarming rate.
There is an article on this subject in a recent issue of Scientific
In our ecosystem oxygen is involved in a number of global cycles: manmade
combustion converting it to CO2, the production of O2 by plankton, plants
etc., two mention just two. In the short term this is a steady state, but
not necessarily a stable one in the long term.
The amount of O2 and H2 generated by electrolysis is globally insignificant,
and in the atmosphere, the relatively large excess of O2 does combine with
any free H2 rather quickly to reform water.
Click here to return to the General Topics Archives
Update: June 2012