Gravitational force is the attractive force between any two masses.
What about gaseous planets, where do they get their attractive force from?
While the big rocky planets don't have enough attractive force to keep enough gases in their gravitational field, Jupiter has lots of gases.
Does this means there is a concentrated mass inside, under which gravitational field the gases are kept 'in'? And if so, then why are gaseous planets not also considered to be rocky ones?