7. The five distant planets are made mostly of .?

The five distant planets, often referred to as the gas giants (Jupiter, Saturn) and ice giants (Uranus, Neptune), are primarily composed of hydrogen, helium, and various ices such as water, ammonia, and methane. While gas giants have thick atmospheres dominated by hydrogen and helium, ice giants possess a higher proportion of heavier elements and ices. These compositions differ significantly from terrestrial planets, which are primarily rocky.