gas planets

[sandman666]

is there a rocky core at the centre of any of the gas planets or are they gas stright through?

[Buenchico]

They're not 'gas' (as we normally think of it) all the way through. Hydrogen, for example is a metal at the centre of such planets.

I hope that you won't be offended if I direct you to a page that's aimed at kids, but it's on the NASA website (which ought to be a reliable source of information!) and it seems to be relevant to your question:
http://spaceplace.nasa.gov/en/kids/phonedrmarc /2003_september.shtml

Chris

[mibn2cweus]

more on (no pun intended) gas giant cores