Why do larger planets tend to mostly be made up of gases?

Question

Why do larger planets tend to mostly be made up of gases?

In: 2

Answer 1

Most of the mass of the solar system (or the universe for that matter) is hydrogen and helium. Other elements only account for about 1-2% of the solar system. Small rocky planets like earth form where gasses such as hydrogen and helium have been driven off, leaving behind a relatively small amount of solid to form those planets. Hydrogen and helium were the only elements present in enough quantity in the protoplanetary disk to form planets as massive as Jupiter and Saturn.