Atomic and nuclear properties of materials:
Arsenic (As)

Quantity	Value	Units	Value	Units
Atomic number	33
Atomic mass	74.92160(2)	g mole-1
Specific gravity	5.73	g cm-3
Minimum ionization	1.370	MeV g-1cm2	7.851	MeV cm-1
Nuclear collision length	87.5	g cm-2	15.28	cm
Nuclear interaction length	144.4	g cm-2	25.19	cm
Radiation length	11.94	g cm-2	2.084	cm
Critical energy	17.65	MeV (for e-)	17.09	MeV (for e+)
Molière radius	14.35	g cm-2	2.504	cm
Plasma energy	45.78	eV
Muon critical energy	290.	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
Table of isotopes
x ray mass attenuation coefficients