A Level Chemistry OCR Practice Exam

Which layer of the Earth's atmosphere is known as the troposphere?

1. The uppermost layer of the atmosphere

2. The layer where weather occurs, extending to about 20 km

3. The layer closest to the Sun

4. The layer with the highest concentration of ozone

The correct answer is: The layer where weather occurs, extending to about 20 km

The troposphere is recognized as the layer where weather phenomena occur, extending up to approximately 20 kilometers above the Earth's surface. This layer is characterized by temperature decreases with altitude, allowing for the formation of clouds and precipitation, which are essential components of weather systems. In this layer, the majority of the atmospheric mass is concentrated, leading to a rich variety of weather-related events such as storms and winds. The location of the troposphere is significant because it interacts with the Earth's surface, influencing both local and global weather patterns. While the other options refer to various atmospheric layers, they do not accurately describe the characteristics or functions of the troposphere. The uppermost layer of the atmosphere is known as the exosphere, and the closest layer to the Sun in terms of solar radiation absorption is the thermosphere, which lies above the mesosphere. Meanwhile, the ozone layer, which contains a high concentration of ozone, is primarily located within the stratosphere, specifically at the stratospheric layer rather than the troposphere.