If an element becoming colder slows the atoms down, which makes them more likely to be solid, than why are all the gas giants furthest from the sun?

Question

If an element becoming colder slows the atoms down, which makes them more likely to be solid, than why are all the gas giants furthest from the sun?

In: Planetary Science

Answer 1

Hydrogen and helium are very light so tended to get blown outwards by solar wind, so there was just a lot more gas in the outer solar system where the gas giants formed. Temperature isn’t so important because even the furthest gas giant Neptune is above the temperature that hydrogen goes from gas to liquid.