Final answer:
The troposphere is the densest layer of Earth's atmosphere and is where all weather phenomena occur. It extends from the Earth's surface up to about 11-13 kilometers in altitude and contains the majority of atmospheric gases and water vapor, essential for cloud formation and weather events.
Step-by-step explanation:
The question pertains to the atmospheric layers of the Earth and seeks to identify which layer is the densest and where weather phenomena occur. Based on the information provided and general understanding of Earth's atmosphere, we can determine that the troposphere is the correct answer to this question. The troposphere is the lowest layer of the Earth's atmosphere, extending from the surface to an altitude of about 11-13 kilometers (7-8 miles). It is in this layer that atmospheric wind and weather are confined.
The troposphere is indeed the densest layer of the atmosphere because it contains about 75% of the atmosphere's mass and almost all of its water vapor and gases, which are essential for cloud formation and weather events. The temperature in the troposphere decreases with ascending altitude. Weather happens in the troposphere due to the presence of water vapor and the turbulent mix of warm and cold air masses.