What is the primary composition of the Earth's atmosphere?

The primary composition of the Earth's atmosphere is indeed a mixture of gases that surrounds the planet. This mixture primarily consists of nitrogen (about 78%) and oxygen (about 21%), with trace amounts of other gases like argon, carbon dioxide, and water vapor. The atmosphere plays a crucial role in supporting life by providing oxygen for respiration, protecting organisms from harmful solar radiation, and helping to regulate the Earth's temperature through the greenhouse effect.

The atmosphere's gaseous nature is essential for various processes, including weather formation and climate regulation. Unlike a layer of liquid or a solid layer, which would not support the diverse range of life forms that exist, the gaseous mixture allows for movement and interaction with the Earth's surface. Thus, the description of the atmosphere as a mixture of gases is accurate and reflects its complex, dynamic nature.