¹³C-Carbon

 
13C has 6 protons and 7 neutrons.
13C is a stable isotope.
The mass excess of 13C is 3125.00933 with an uncertainty of ±0.00023.


The mass was measured using a Penning Trap and the related equations include:

Influence				 Equations

      78.2%			  13CH-14N  1  
      21.8%			13CH2-28Si  2  
            0.2%			   136Xe-13C3O6  3  









Reference

1. Simon Rainville, James K. Thompson, David E. Pritchard (2004), An Ion Balance for Ultra-High-Precision Atomic Mass Measurements Science 
303(5656)
	 https://www.science.org/doi/10.1126/science.1092320 

2. Matthew Redshaw, Joseph McDaniel, and Edmund G. Myers (2008), Dipole Moment of PH+ and the Atomic Masses of 28Si,31P by Comparing Cyclotron Frequencies of Two Ions Simultaneously Trapped in a Penning Trap
  Physical Review Letters, 100(9)
  https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.100.093002

3. Matthew Redshaw, E. Wingfield, Joseph McDaniel, and Edmund G. Myers (2007), Mass and Double-Beta-Decay Q Value of 136Xe
  Physical Review Letters, 98(5) 
  https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.98.053003