Atmospheric pressure

Atmospheric pressure is defined as the force per unit area exerted against a surface by the weight of air above that surface in the Earth's atmosphere.

Here I am also providing you a link on the definition of pressure.You can get the clear concepts of pressure here.

There is less atmospheric mass where there is low pressure areas  above their location, whereas high pressure areas have more atmospheric mass above their location. Similarly,when elevation increases there is less overlying atmospheric mass, so that pressure decreases with increasing elevation.

How to calculate atmospheric pressure:You can see atmospheric pressure calculator to know how to calculate atmospheric calculator.By using the Barometric Formula,

P = Mass/Volume = (nNAm)/nRT / P
R/NA = K

n = number of moles

NA = Avogadro number

m = mass of one molecule

K = Boltzmann constant

R = Gas constant

You can always refer my blog for science help , and also send in your comments and suggestions.