What is the atmosphere?

• A. Layer of land
• B. Layer of gases surrounding a planet providing oxygen and regulating temperature
• C. The ozone layer only
• D. The layer of water vapor in clouds

Answer: (B)

Atmosphere is the layer of gases surrounding a planet, providing the air we breathe and helping regulate temperature and climate. It isn’t land or water; it’s the gaseous envelope above the surface. The ozone layer is a part of this envelope that absorbs ultraviolet radiation, but it’s not the entire atmosphere. Water vapor is just one component, forming clouds and humidity, while the atmosphere includes many other gases as well. On Earth, it’s mainly nitrogen and oxygen, with smaller amounts of argon, carbon dioxide, neon, and others, all contributing to air pressure that drives weather and protects life.