136Xe has 54 protons and 82 neutrons.
136Xe is a stable isotope.
The mass excess of 136Xe is -86429.17 with an uncertainty of ±0.007.
The mass was measured using a Penning Trap and the related equations include:
Influence Equations
80.9% 136Xe-13C3O6 1
19.1% 136Xe-28Si4D12 1
Reference
1. M. Redshaw, E. Wingfield, J. McDaniel, E.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