Atomic and nuclear properties of polonium (Po)
QuantityValueUnits ValueUnits
Atomic number 84     
Atomic mass [208.98243(2)] g mole-1   
Specific gravity 9.320 g cm-3   
Mean excitation energy 830.0 eV   
Minimum ionization 1.141 MeV g-1cm2 10.63 MeV cm-1
Nuclear collision length 114.3 g cm-2 12.27 cm
Nuclear interaction length 200.2 g cm-2 21.48 cm
Pion collision length 137.6 g cm-2 14.76 cm
Pion interaction length 226.7 g cm-2 24.32 cm
Radiation length 6.16 g cm-2 0.6611 cm
Critical energy 7.33 MeV (for e-) 7.06 MeV (for e+)
Molière radius 17.83 g cm-2 1.913 cm
Plasma energy ωp 55.77 eV   
Muon critical energy 140. 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
Note: Since there are no stable isotopes, [atomic mass] is that of the longest-lived isotope known as of Jan 2007.
Table of isotopes Warning: may not be current
x ray mass attenuation coefficients