I think that "0.3" is probably meant to be 0.3 AU. The answer is: the denser substances of the solar system which later formed the rocky inner planets. The gases were likely to form gas giant planets, further away from the Sun.
Outer planets and inner planets are compared because they have distinct differences in size, composition, and characteristics. Inner planets are smaller, rocky, and denser, while outer planets are larger, gaseous, and have thick atmospheres. Studying these differences helps scientists understand how planets form and evolve in our solar system.
Most of the gasses were swept out of the inner solar system by the solar wind, leaving rock as the most abundant material to form planets and moons.
The Solar System is a oval because that how the planets form it .
A solar system!
Dust grains, ice particles, and rocky fragments were present as solid flakes in the inner 0.3 AU of the solar system before planets formed. These materials gradually accreted and collided to form planetesimals, which later grew into protoplanets and finally, the inner terrestrial planets we see today.
By mass, the majority of the matter orbiting the sun is hydrogen and helium. When the solar system was just starting to form heat from the sun and the strong solar wind drove most of the hydrogen, helium, and other gasses out of the inner solar system, leaving behind mostly rock and metal, which were much less abundant. The sunlight and solar wind in the outer solar system were much less intense, so these gasses remained in place long enough to become part of the giant planets.
Within the inner 0.3 AU of the solar system before planets began to form, solid flakes of materials such as silicates, metals, and ices would have been present. These materials likely condensed from the hot protoplanetary disk surrounding the young Sun, forming the building blocks that eventually came together to form the planets.
rocks, metals, hydrogen compounds, hydrogen, and helium, all in gaseous form
No. They form in the outer solar system where it is cold enough.
The solar system is estimated to be approximately 5 billion years old.
Asteroids, comets, planets, the Sun and other object form the solar system