Final answer:
The outer planets in our solar system, known as gas giants or ice giants, have atmospheres primarily composed of hydrogen-based gases such as methane and ammonia. Uranus and Neptune, the ice giants, contain larger amounts of ice compared to Jupiter and Saturn.
Step-by-step explanation:
The outer planets in our solar system, namely Jupiter, Saturn, Uranus, and Neptune, are primarily composed of hydrogen and helium gases. These planets are often referred to as 'gas giants' due to the dominance of gases in their atmospheres. However, Uranus and Neptune, which contain larger amounts of ice compared to Jupiter and Saturn, are sometimes called 'ice giants.'
The atmosphere of these outer planets consists mainly of hydrogen-based gases such as methane and ammonia. They may also contain more complex hydrocarbons like ethane and acetylene. The chemistry of these giant planet atmospheres is reducing, meaning that hydrogen tends to combine with other elements first.