The Indianapolis times., 1924-04-12
ELECTRON
ORBITS ARE
FIXED ZONES
Molecules Are Grouped in Al
most Any Conceivable
Shape,
BY DAVID DIETZ
Science Editor of The Times

Copyright by David Dietz
TT LECTRONS, it will be rcmem-
r bered, seem to group them
III selves into atoms along def
mite configurauons, revolving in or
bits that seem to be arranged by
zones.
There does not seem to be any
such simple statement of the way in
which atoms group themselves into
molecules
Apparently they form molecules Of
almost any conceivable shape
There are reasons for believing that
the characteristics or properties of a
mpound-hardness color and so on
are due not only to the kind and
number of atoms in its molecule but
the way in which the atoms are
grouped. That is, their geometrical
design.
Many atoms apparently possess the
property of grouping themselves
into molecules in different ways.
over 1000 compounds of the ele
ment carbon are known. Most of
these consist only of the combination
of carbon atoms with three other
atoms, hydrogen, oxygen and nitro
gen.
Difference in Pattern
Frequently two different com
pounds are known which consist OF
exactly the same number and kinds
of atoms Here the sole differen-
tiation between the two compounds
oh,
the atoms are arranged,
Carbon is again the most prolific
i'm this field. There are twenty-six
different compounds the molecules
OF each one consisting of four atoms
OF carbon. six Of hydrogen and three
OF oxygen. But in each Of the
twenty-six the atoms are arranged
in different pattern.
Compounds such as these are called
"isomers" by the chemist.
In some complicated molecules it !
appears as though the atoms we're
arranged in q ring.
The chemist is able to produce new
compounds by producing chemical
reactions which result in one atom
being substituted for another in the
ring. Sometimes he is able to sub
stitute a group Of atoms for one atom. /
We also find an interesting molec- I.
ular structure in the elements them
selves Thus i'm the element oxygen
we find the atoms of oxygen com
bined in pairs to form molecules OF
oxygen.
Some elements exist in different
III a. terrfs
are both found in two forms. the
yellow and the red It is thought that
the reason for this Is that the atoms
may combine in two different ways
to form molecules.
Two Kinds oe Atoms
Physicists have recently discovered
that sometimes there can be more
than one kind of atom for q particu-
lar element Thus mercury has
been found to be a mixture of
two kinds of atoms. The two act
exactly alike for both have the same
number of outer electrons revolving
around them One, however, has
more electrons in the nucleus than the
other. However, in both cases the
preponderance Of positive over mega
tive electrons in the nucleus are alike.
Atoms which differ in weight. but
which act alike are called 'isotopes"
by the chemist.
Recent experimental work has led
many physicists to believe that true
molecules exist as separate entities
only in gases and liquids but that a
sort of interIocking arrangement ex-
lists between the molecules Of all sol.
IDS so that it is impossible to say
where one molecule ends and another
begins.
This is the theory Of crystal struc-
ture.
Next article in series Crystal Struc-
ture.