"Atmosphere":
The atmosphere is a protective layer of gases surrounding the Earth, extending up to 700 km. It consists primarily of nitrogen (78%) and oxygen (21%), which are essential for life. The atmosphere is divided into five layers: the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. Each layer has its own unique features. For example, the troposphere is where weather occurs, and the stratosphere contains the ozone layer, which shields Earth from harmful ultraviolet rays. The atmosphere also plays a critical role in regulating the planet’s temperature by trapping heat and supporting the hydrological cycle. It provides the necessary gases for respiration and photosynthesis, making life on Earth possible. Understanding the structure and function of the atmosphere helps us appreciate its importance and underscores the need to protect it from pollution and other environmental threats.