Jupiter's atmosphere consists mainly of hydrogen (90%) and helium(9%). how does this mixture of gases contrast with the composition of earth's atmosphere? why does the composition differ. note : chegg site solution is not correct. so me on it.

The atmospheric composition of Jupiter and Earth both differs from one another. Jupiter is comprised of mainly hydrogen and helium, where hydrogen content is about 90%, helium content is approximately 9% and the remaining gases includes methane, ammonia along with a thick layer of metallic hydrogen.

Whereas, Earth is consist of almost 78% of nitrogen, 21% of oxygen, about 1% of Argon and some amount of carbon dioxide (CO₂) and water vapor (H₂O) in its atmosphere.

There is significant difference in atmospheric composition in both the planets. It is because that the earth is much closer to the sun in comparison to Jupiter, and Jupiter is a gas giant that is mainly comprised of variable gases and abundance of ice in it. But Earth on the other hand, being closer to the sun, the hydrogen and helium that it initially had, were all probably evaporated. As a result of which these gases are absent.