Question

WHAT'S the DIFFERENCE B/W 1Bar.............. AND ''atm''??

Answer 1

atmosphere is about 101.325 kilopascals. Barometer is a device used to measure the atmospheric pressure. Bar is the atmospheric pressure at the sea level, which is around 100 kilopascals. Since the difference between atm and bar is so small, in most applications bar unit is used.

Answer 2

1 bar is the SI unit of pascal
atm is used in standard temperature