Atomic and nuclear properties of thorium (Th)

Quantity	Value	Units	Value	Units
Atomic number	90
Atomic mass	[232.0377(4)]	g mol-1
Density	11.72	g cm-3
Mean excitation energy	847.0	eV
Minimum ionization	1.098	MeV g-1cm2	12.87	MeV cm-1
Nuclear interaction length	207.3	g cm-2	17.68	cm
Nuclear collision length	117.7	g cm-2	10.05	cm
Pion interaction length	233.2	g cm-2	19.90	cm
Pion collision length	140.7	g cm-2	12.01	cm
Radiation length	6.07	g cm-2	0.5182	cm
Critical energy	6.91	MeV (for e-)	6.66	MeV (for e+)
Muon critical energy	132.	GeV
Molière radius	18.64	g cm-2	1.590	cm
Plasma energy ℏωp	61.44	eV
Melting point	1408.	K	1135.	C
Boiling point @ 1 atm	4404.	K	4131.	C

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: There is a well-defined terrestrial aboundance for thorium even though it is radioactive.
Table of isotopes via WIKIPEDIA
x ray mass attenuation coefficients from NIST