Atomic and nuclear properties of americium (Am)

Quantity	Value	Units	Value	Units
Atomic number	95
Atomic mass	[243.06138(2)]	g mole-1
Specific gravity	13.67	g cm-3
Mean excitation energy	934.0	eV
Minimum ionization	1.089	MeV g-1cm2	14.88	MeV cm-1
Nuclear collision length	119.3	g cm-2	8.727	cm
Nuclear interaction length	210.5	g cm-2	15.40	cm
Pion collision length	142.2	g cm-2	10.40	cm
Pion interaction length	236.7	g cm-2	17.31	cm
Radiation length	5.80	g cm-2	0.4243	cm
Critical energy	6.50	MeV (for e-)	6.25	MeV (for e+)
Molière radius	18.93	g cm-2	1.385	cm
Plasma energy ℏωp	66.61	eV
Muon critical energy	127.	GeV

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: Since there is no stable isotope, [atomic mass] is that of the longest-lived isotope known as of Jun 2017.
Table of isotopes via WIKIPEDIA