What is the correct equivalence for 1 atmosphere in pascals and kilopascals?

• A. 1 atm equals 100000 Pa.
• B. 1 atm equals 101325 Pa and 101.3 kPa.
• C. 1 atm equals 1,000 Pa.
• D. 1 atm equals 10.13 kPa.

Answer: (B)

Atmospheric pressure is defined by a precise standard value: 1 atmosphere equals 101,325 pascals, which is the same as 101.325 kilopascals (since 1 kPa = 1000 Pa). Saying it as 101.3 kPa is a common rounding to three significant figures. So the correct statement lists both the exact pascal value and the kilopascal value, matching the standard definition. The other options misstate the magnitude—100,000 Pa is 100 kPa, not 101.325 kPa; 1,000 Pa is far too small for atmospheric pressure; and 10.13 kPa is about one-tenth of a standard atmosphere.