From Wikipedia,
the free encyclopedia.
CHON is an
mnemonic
acronym for the four most
common
elements in living organisms:
carbon,
hydrogen,
oxygen, and
nitrogen. These four elements
are also notable for being the
least massive (and having the
lowest
atomic number) in their
group in the
periodic table.
Carbonaceous asteroids are
rich in CHON elements. These
asteroids are the most common type
and frequently collide with Earth
(as
meteorites). Such collisions
were especially common early in
Earth's history and these
meteorites may have been crucial
in the
formation of life on Earth.
Excluding
noble gases, the CHON elements
are the most common:
- the main ingredients [of the
primordial soup] are also
some of the most abundant -
Carbon (4th most abundant),
Hydrogen (most abundant), Oxygen
(3rd) and Nitrogen (6th) - CHON.
(The other abundant elements,
Helium and
Neon, are both inert - they
do not react with other
elements)[1]
CHON is featured in
science fiction as the
elements needed to sustain life in
space colonies or as a
lucrative space
industry. In particular, CHON
featured prominently in
Frederik Pohl's Beyond the
Blue Event Horizon which had
an
overpopulated Earth with 25
billion inhabitants. In this
novel, a CHON "food factory" was
discovered in the
Oort cloud. This factory was
mining carbonaceous asteroids
which are high in CHON elements.
Sometimes the acronym CHONP is
used to include the element
phosphorus which is crucial in
DNA and
RNA. Further, the acronym
CHON(PS) may be used which is:
- CHON (Carbon, Hydrogen,
Oxygen and Nitrogen) plus (SP:
Sulphur [or sulfur],
Phosphorous) 99% of all living
systems[2]
Sulfur is used in the
amino acids
cysteine and
methionine.
