Question

the envelop which surrounds the earth with unknown thickness is called ______​

Answer 1

Answer:

The atmosphere is a gaseous envelope surrounding the earth. It is mostly composed of nitrogen, oxygen, argon, carbon dioxide and some other gasses in trace amounts. The atmosphere is held in place by gravity of the earth.

Answer 2

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The atmosphere is the thin envelope of gas molecules surrounding the Earth; it is held down by Earth's gravitational pull. The atmosphere is concentrated at the Earth's surface and rapidly thins as you move upward, blending with space at about 100 miles above sea level.