Final answer:
The statement that Jupiter's interior is mostly liquid helium is false; it is predominantly composed of compressed hydrogen, with significant portions in a metallic, liquid-like state, and helium being the secondary component.
Step-by-step explanation:
False. Jupiter's interior is not mostly liquid helium, but rather it is composed predominantly of hydrogen and helium with hydrogen being the more abundant element, making up 75% of the planet's mass. Within Jupiter, due to immense pressure, these elements are compressed to the point where hydrogen becomes metallic and acts like a liquid. This composition and state are similar to those of Saturn.
These planets are often referred to as gas giants, but given the physical state of the elements under such extreme pressure, the term liquid planets is more apt. Interestingly, at even higher pressures inside Jupiter, hydrogen takes on a metallic form, which behaves very differently from its conventional state on Earth.