Atomic and nuclear properties of polonium (Po)
QuantityValueUnits ValueUnits
Atomic number 84     
Atomic mass [208.98243(2)] g mol-1   
Density 9.320 g cm-3   
Mean excitation energy 830.0 eV   
Minimum ionization 1.141 MeV g-1cm2 10.63 MeV cm-1
Nuclear interaction length 200.2 g cm-2 21.48 cm
Nuclear collision length 114.3 g cm-2 12.27 cm
Pion interaction length 226.4 g cm-2 24.29 cm
Pion collision length 137.6 g cm-2 14.76 cm
Radiation length 6.16 g cm-2 0.6611 cm
Critical energy 7.33 MeV (for e-) 7.06 MeV (for e+)
Muon critical energy 140. GeV   
Molière radius 17.83 g cm-2 1.913 cm
Plasma energy ωp 55.77 eV   
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
Note: Since there are no stable isotopes, [atomic mass] is that of the longest-lived isotope known as of Jun 2017.
Table of isotopes via WIKIPEDIA
x ray mass attenuation coefficients from NIST