NCERT Solutions For Class 12. The molar mass of nitrogen N 2 and oxygen O 2 are 28014 g mol 1 and 31998 g mol 1 respectively. Nitrogen Definition Symbol Uses Properties Atomic Number Facts Nitrogen Electron Configuration Kindergarten Skills The reported uncertainties of the standard atomic weights are such that the atomic-weight values of normal materials are expected to lie in the given interval with great certitude. . This works because neutrons and protons are both very close to 1 AMU and electrons are very close to 0 AMU. Build an atom out of protons neutrons and electrons and see how the element charge and mass change. Round to the mass number. This way we can calculate the molar mass of a compound or one-carbon compound. The origin of the name comes from the Greek words nitron genes meaning nitre and forming and the Latin word nitrum nitre is a common name for potassium nitrate KNO3. The resulting atom is nitrogen-14