QUESTION:
In a previous answer you describe the possibility of finding a
solid hydrogen material on the  surface of Jupiter, perhaps due to the
extreme pressure in the nucleus of the planet.

If the Hydrogen gas suffers a tremendous pressure, ins't it more likely
that the Hydrogen element be converted into another element like
B, C, N O2 or Fe instead of being converted to solid Hydrogen?

ANSWER from Duane L. Bindschadler on January 15, 1996:
Well, you certainly might think so. However, the process that would
convert Hydrogen to some other element occurs in only one place in
nature -- inside of stars. That's because the only way to get one
element to convert to another one is to get the nuclei of atoms
(the central part containing protons and neutrons) to interact with
one another. This is very hard to do, because:

(1) Atoms have electrons which surround the nuclei and tend to
    repel one another. If you push to atoms up against one another
    when their electrons are intact, they are either forced apart,
    or, in some cases, they will combine to form molecules.

(2) The sub-atomic particles that make up nuclei also tend to repel
    one another. Even if electrons are removed, the mutual repulsion
    between nuclei has to be overcome.

In the central parts of stars, there is extreme heat and pressure.
The combination of these two things strips atoms of their electrons,
and forces the remaining nuclei into frequent collisions, in which
new atoms are made. For example, in our Sun, the fusion reaction
(that is, the reaction that occurs when nuclei collide with one
another and with other subatomic particles) takes Hydrogen and
converts it to Helium.

What seems to happen inside Jupiter is that the Hydrogen atoms are
forced close enough that they all share the available electrons.
That is, instead of each Hydrogen nucleus having a single electron,
all Hydrogen nuclei share all the available electrons. That means that
electrons are free to move throughout the metallic Hydrogen. But
the pressure and temperature don't reach the point where nuclear
fusion can occur.