⁴⁰K-Potassium

 
40K has 19 protons and 21 neutrons.
40K is a stable isotope.
The mass excess of 40K is -33535.497 with an uncertainty of ±0.056.


The mass was measured using Nuclear Physics and the related equations include:

Influence				 Equations

         60.9%		  	        39K(n, γ)40K  1  
		         39.1%			        40K(n, γ)41K  2  		  
         
		 









Reference

1. T. Von Egidy, H. Daniel, P. Hungerford, H.H. Schmidt, K.P. Lieb, B. Krusche, S.A. Kerr, G. Barreau, H.G. Borner, R. Brissot, C. Hofmeyr, R. Rascher (1984)
Levels and gamma transitions of 40K studied by neutron capture  Journal of Physics G: Nuclear Physics  10(2)
https://iopscience.iop.org/article/10.1088/0305-4616/10/2/013

2. B. Krusche, K.P. Lieb, L. Ziegler, H. Daniel, T. von Egidy, R. Rascher, H.G. Borner, G. Barreau, D.D. Warner (1984)
Spectroscopy of 41K by thermal neutron capture in 40K  Nuclear Physics A  417(2)
https://doi.org/10.1016/0375-9474(84)90506-2