Question

Define atmosphere and atmosphere pressure.

Answer 1

Hint: We know that atmosphere is a very commonly used term. Atmosphere pressure from the very name we could guess that it must be some pressure that is directly related to the atmosphere. You could simply recall the correct definitions of these two terms and thus answer the question.

Complete solution:
In the question, we are asked to define the atmosphere as well as atmospheric pressure.
Atmosphere is basically the layer that surrounds a planet or any other material body. The atmosphere is held in place with the help of gravity of that body that is surrounded.
We could define atmospheric pressure just like any pressure as the force acting per unit area. But, the difference here is that the force here is known to be exerted by the atmospheric column or the air column above a body. This pressure can be measured using a mercury barometer. Mercury barometer is that device in which the height of a column of mercury balances the weight of the column of atmosphere and thus we could take the measurement. Then, we have aneroid barometer which has multiple sensing elements that are hollow, partially evacuated, corrugated metal disks supported against collapse by an inside or outside spring; when the disk is subjected to a change in shape by changing pressure, we could record using a pen arm or a clock driven revolving drum.

Note:
Our atmosphere is known to be composed of various gases like nitrogen, oxygen, argon, carbon dioxide and many other gases in trace amounts. We should know that earth’s atmospheric pressure is measured as one standard atmosphere at sea level. Which is known to have the value of $1.013\times {{10}^{5}}N{{m}^{-2}}$.