How did the temperature structure of the solar nebula determine planetary composition?

Question

How did the temperature structure of the solar nebula determine planetary composition?

Answer 1

The temperature of the solar nebula was greatest in the center, and decreased as distance from the center increased.  At any given location, the only materials to condense out were those able to survive the temperature there.  In the innermost regions, around Mercury's present orbit, only metallic grains could form.  A little farther out, at about 1 A.U., it was possible for rocky, silicate grains to form, too. Beyond about 3 or 4 A.U., water ice could exist, and so on, with the condensation of more and more material possible at greater and greater distances from the Sun. The composition of the material that could condense out at any given radius would ultimately determine the types of planets that formed there.

Fragments destined to become the cores of the jovian planets were formed under cold conditions out of low-density, icy material.

In the inner regions of the primitive solar system, condensation from gas to solid began when the average temperature was about 1000 K. The environment there was too hot for ices to survive. Many of the abundant heavier elements, such as silicon, iron, magnesium, and aluminum, combined with oxygen to produce a variety of rocky materials. Planetesimals in the inner solar system were therefore rocky in nature, as were the protoplanets and planets they ultimately formed.