Atomic and nuclear properties of materials:
UNCONFIRMED Element 118
Status as of January 2007 (pdf)

Quantity	Value	Units	Value	Units
Atomic number	118
Atomic mass	[298.]	g mole-1
Specific gravity (20° C, 1 atm)	1.20E-02	g cm-3
Minimum ionization	1.078	MeV g-1cm2	1.294E-02	MeV cm-1
Nuclear collision length	126.5	g cm-2	1.054E+04	cm
Nuclear interaction length	225.3	g cm-2	1.878E+04	cm
Radiation length	4.95	g cm-2	412.1	cm
Critical energy	5.67	MeV (for e-)	5.45	MeV (for e+)
Molière radius	18.49	g cm-2	1541.	cm
Plasma energy	1.99	eV
Muon critical energy	129.	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: Atomic mass is that reported by the researchers as of Jan 2007.
Note: Density is for an ideal monotomic gas.
Note: I_eff = 1242 eV assumed in calculating critical energies and dE/dx.