Atomic and nuclear properties of potassium (K)
QuantityValueUnits ValueUnits
Atomic number 19     
Atomic mass 39.0983(1) g mole-1   
Specific gravity 0.8620 g cm-3   
Mean excitation energy 190.0 eV   
Minimum ionization 1.623 MeV g-1cm2 1.399 MeV cm-1
Nuclear collision length 75.4 g cm-2 87.44 cm
Nuclear interaction length 119.0 g cm-2 138.0 cm
Pion collision length 101.0 g cm-2 117.2 cm
Pion interaction length 148.1 g cm-2 171.8 cm
Radiation length 17.32 g cm-2 20.09 cm
Critical energy 31.62 MeV (for e-) 30.72 MeV (for e+)
Molière radius 11.61 g cm-2 13.47 cm
Plasma energy ωp 18.65 eV   
Muon critical energy 472. GeV   
For muons, dE/dx = a(E) + b(E) E. Tables of b(E): PDF TEXT
Table of muon dE/dx and Range: PDF TEXT
Explanation of some entries
Table of isotopes via WIKIPEDIA
x ray mass attenuation coefficients from NIST