大氣層中氧氣占百分幾???

係一樣嫁

合成物 佔有量(體積比) 功用
氮氣 78.084% 維持植物生長
氧氣 21.946% 維持生命和幫助燃燒
二氧化碳 0.037% 保持地面溫暖
臭氧 0.000004% 抵擋有害的紫外線輻射
其它氣體 ?
水蒸氣 無常 影響天氣狀況
固體粒子，包括灰塵、火山灰等等 ? 對雲和雲霧的形成非常重要

都係一樣ga...只不過空氣係大氣層愈高就愈稀薄

Oxygen is usually 21% in all layers of the atmosphere.

When we go to high mountains, we have difficulties in breathing. It is not because of the low percentage of oxygen, but is due to the low pressure of air.

Therefore, when the diaphragm flattens to lower the air pressure in rib cage, the air pressure outside is to low that air can't get into the lungs easily.

五分之一.

係一樣的。大氧層中21%係氧氣。

大氣的主要成分
氮氣~78.084%
氧氣~21.946%
二氧化碳~0.037%
臭氧~0.000004%

大約佔五分之一。