Atmosphere of Earth

Air is the Earth's atmosphere, a layer of gases surrounding the planet and retained by Earth's gravity. It is essential for life on Earth as it provides the necessary gases for respiration and other biological processes. The composition of air includes approximately 78% nitrogen, 21% oxygen, 0.9% argon, 0.04% carbon dioxide, and trace amounts of other gases. The term "air" is derived from the Latin word aer or aēr, which itself is believed to have originated from the Greek word ἀήρ (aḗr, "mild, burning"). In Hebrew, air is referred to as אוֹויר (avir), while in Spanish it is aire, in French air, and in German Luft. Air plays a crucial role in weather patterns, climate, and the water cycle, making it a vital component of the Earth's systems. It also serves as a medium for the propagation of sound and the dispersion of seeds and spores, facilitating the spread of life and the maintenance of ecosystems.