Atomic and nuclear properties of materials:
Actinium (Ac)
QuantityValueUnits ValueUnits
Atomic number 89     
Atomic mass [227.0278] g mole-1   
Specific gravity 10.1 g cm-3   
Minimum ionization 1.112 MeV g-1cm2 11.19 MeV cm-1
Nuclear collision length 117.0 g cm-2 11.62 cm
Nuclear interaction length 205.8 g cm-2 20.43 cm
Radiation length 6.06 g cm-2 0.6016 cm
Critical energy 7.00 MeV (for e-) 6.75 MeV (for e+)
Molière radius 18.34 g cm-2 1.821 cm
Plasma energy 57.25 eV   
Muon critical energy 134. GeV   
For muons, dE/dx = a(E) + b(E) E. Tables of b(E): PS PDF TEXT
Table of muon dE/dx and Range: PS PDF TEXT
Explanation of some entries
Note: Since there is no stable isotope, given atomic mass is that of the longest-lived known isotope as of Jan 2007.
Table of isotopes
x ray mass attenuation coefficients