Evening star., 1949-10-14
Bureau Physicists Study
Hot Element Prometheum
One of Original Metals of Universe
Is 500 Times Hotter Than Radium
Bv Thomas X. Henry

Is 500 Times Hotter Than Radium
By Thomas X. Henry
An element 500 times hotter than radium
is being studied by Bureau of Standards
physicists.
It is prometheum, one of the rare earth
metals which presumably was one of the
original elements which went into the COM
position of the universe. All that ever was
present on earth, however, must have dis
appeared we'll over 1000, 100000 years ago
and ever since the atomic table was con-
structed it has been listed as one of the
lost elements which theoretically should
exist but of which no trace could be found.
The sample now being investigated by
DR.. William F. Meggers, head of the Bureau
OF Standards spectroscopy section, weighs
about a sixth -thouSandth of an ounce and
is practically all that now exists in the world.
Half Life of Four Years.
1t has a half life of a little more than
four years. This means that of any number
of prometheum atoms originally present
half will explode in this period. Each will
shoot out an electron from it's nucleus
and thus be transmitted into the next lower
element in the atomic table, another rare
element known as neodyimum. Then in
another four years half of what remains
will likewise be transmitted until eventually
eAAS
to point where it cannot be detected
Radium has a half life of practically
5000 years. Thus the prometheum radiation
is much more intense being exceeded only
by the new synthetic element curium which
is built up from uranium.
All the prometheum now on earth is the
result of the splitting in two of atoms of
uranium 235, the source of the energy of
the atom bomb. The split halves are un-
pOlIal and each has a element
than 40 such elements have been identified,
most of them well known to physicists.
Prometheum is a notable exception.
DR.. Meggers' job is to determine the spec
trum of the element and the structure of
its atom This is accomplished by render
ing it luminous and photographing a spec
trum of the light it emits The light of
each of the 90 elements is unique, consisting
of wave lengths that are not duplicated in
the light from any other element.
Hundreds of new wave lengths hitherto
unknown in nature, have been found in
prometheum.
In its physical properties. the Bureau of
Standards physicists find. the lost element
is closest to the rare element samarium.
This is one of the so-called rare earths for
which no use ever has been found. 1t can
be reduced-as presumably could prone
theum-into soft, gray metal.
hurtling ball of rock about mile in
diameter, latest discovered of the hundreds
of minor planets which circle the sun, is
forcing astronomers to abandon some of
their ideas of the origin of the solar system.
1t also may serve as means of weighing
with far greater accuracy the little planet
Mercury, closest and hottest of the suns
family.
Discovered about a month ago by DR..
Walter Baade of the Mount Wilson Observa-
tory, this little stone in the sky approaches
closer to the earth than any other celestial
body with the exception of the moon. 1t is
about 100000 miles away at it's closest
approach.
Passes in Mercury's Orbit.
Alone of the Lice of the sky" as the
minor planets sometimes are called, this
one actually passes inside the orbit of the
planet Mercury and comes within a little
more than 100000 miles from the sum-
At such time its surface temperature must
be about 1000 Fahrenheit. 1t is probably
hot enough to be family luminous. It's great
est distance from the sun is about 156 900 900
miles, when it recedes into the orbit of Mars
Until quite recently all the minor planets
were believed to be confined to the space
between Mars and Jupiter and to be the
remains of some large planet which once
filled that position and was broken up into
small pieces. Now several have been found
far inside Mars orbit, and theories of the
evolution of the solar system based on their
distribution must be discarded
Because of the close approach to Mercury
some estimate of the mass of that planet
may be made from the observed gravitational
effect.
There is possibility. it is claimed that
the new minor planet is what is left of a
comet from which the tail has been swept
by its close approaches to the sun.