What is the core of Jupiter thought to be composed of?
iron
helium
hydrogen
ice and rock

The atmosphere of Jupiter is 90 percent hydrogen. The remaining 10 percent is almost completely made up of helium, though there are small traces of other gases inside.

Explanation:

Composed predominantly of hydrogen and helium, the massive Jupiter is much like a tiny star. But despite the fact that it is the largest planet in the solar system, the gas giant just doesn't have the mass needed to push it into stellar status.

The atmosphere of Jupiter is 90 percent hydrogen. The remaining 10 percent is almost completely made up of helium, though there are small traces of other gases inside.

These gases pile on top of one another, forming layers that extend downward. Because there is no solid ground, the surface of Jupiter is defined as the point where the atmospheric pressure is equal to that of Earth. At this point, the pull of gravity is almost two and a half times stronger than it is on our planet.