Atomic and nuclear properties of materials:
Silica aerogel for rho = 0.2 (0.03 H₂O, 0.97 SiO₂)

Quantity	Value	Units	Value	Units
<Z/A>	0.50093
Specific gravity	0.200	g cm-3
Minimum ionization	1.740	MeV g-1cm2	0.3480	MeV cm-1
Nuclear collision length	65.0	g cm-2	324.9	cm
Nuclear interaction length	97.3	g cm-2	486.7	cm
Radiation length	27.25	g cm-2	136.3	cm
Critical energy	56.07	MeV (for e-)	54.63	MeV (for e+)
Molière radius	10.31	g cm-2	51.53	cm
Plasma energy	9.12	eV
Muon critical energy	762.	GeV

Composition:

Elem	Z	Atomic frac*	Mass frac*
O	8	2.00	0.543192
Si	14	1.00	0.453451
H	1	2.00	0.003357
* calculated from mass fraction data.

Explanation of some entries
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
Note: See A. R. Buzykaev et al, NIM A433 396 (1999)