Like other Substance, air has weight. Composed of nitrogen, oxygen, carbon dioxide and other gases, it surrounds the earth like an envelope. And, it extends almost a thousand kilometers above the Earth’s surface.
Air Weight is the mass per unit volume of Earth’s atmosphere. The weight of air, like air pressure, decreases with increasing altitude. It also changes with variation in temperature or humidity.
WEIGHT OF AIR AND ALTITUDE
A little change in the atmospheric pressure can make us feel sick. This is the reason why mountaineers get sick at high altitudes. As we go higher, the air becomes thin and hence, the atmospheric pressure also decreases.
Air is a real substance and it has weight. That is why it weighs 14.7 pounds per square inch at sea level. What scientists mean when they give this figure is that if a column of air one square inch in size from sea level to the top of the atmosphere above Earth would weigh 14.7 pounds.
If you travel up over a mountain pass air pressure decreases as you move upward. At 18,000 feet above the Earth the air pressure is approximately 7.35 pounds per square inch or half the atmosphere at sea level.