Since I don't really know a lot of this stuff myself I think I had better put up some statistics of our prey. I selected some relevant bits of information selected statistics from the all powerful wikipedia, if you need some more information here is the link.
Equatorial radius: 71,492±4 km (11.209 Earths)
Polar radius: 66,854±10 km (10.517 Earths)
Surface area: 6.21796×1010 km² (121.9 Earths)
Volume: 1.43128×1015 km³ (1321.3 Earths)
Mass: 1.8986×1027 kg (317.8 Earths)
Mean density: 1.326 g/cm³
Equatorial surface gravity: 24.79 m/s² (2.358 g)
Escape velocity: 59.5 km/s
Sidereal rotation period: 9.925 h
Rotation velocity at equator: 12.6 km/s 45,300 km/h
Surface pressure: 20–200 kPa (cloud layer)
89.8±2.0% Hydrogen (H2)
~0.003% Hydrogen deuteride (HD)
quoting the internal structure section of the wiki entry
"Jupiter may possess a dense, rocky core with a mass of up to twelve times the Earth's total mass; roughly 3% of the total mass. The core region is surrounded by dense metallic hydrogen, which extends outward to about 78% of the radius of the planet. Rain-like droplets of helium and neon precipitate downward through this layer, depleting the abundance of these elements in the upper atmosphere.
Above the layer of metallic hydrogen lies a transparent interior atmosphere of liquid hydrogen and gaseous hydrogen, with the gaseous portion extending downward from the cloud layer to a depth of about 1,000 km. Instead of a clear boundary or surface between these different phases of hydrogen, there may be a smooth gradation from gas to liquid as one descends.
The temperature and pressure inside Jupiter increase steadily toward the core. At the phase transition region where liquid hydrogen (heated beyond its critical point) becomes metallic, it is believed the temperature is 10,000 K and the pressure is 200 GPa. The temperature at the core boundary is estimated to be 36,000 K and the interior pressure is roughly 3,000–4,500 GPa."
Pay close attention to the part about most of the diameter of jupiter being metalic hydrogen that turns out to be important.