Muon radiative energy loss (in 1.0E06 cm^2/g) in rubidium (Rb) with Z = 37, A = 85.4678(3) (f12.0,4f12.4) E (GeV) b_brem b_pair b_nucl b_total 2. 1.0531 0.4733 0.3952 1.9216 5. 1.4453 1.2442 0.4220 3.1115 10. 1.7640 1.8439 0.4030 4.0110 20. 2.0911 2.4395 0.3918 4.9224 50. 2.5221 3.3192 0.3802 6.2215 100. 2.8311 3.9118 0.3718 7.1147 200. 3.1165 4.4465 0.3678 7.9308 500. 3.4420 4.9468 0.3678 8.7565 1000. 3.6417 5.2165 0.3736 9.2318 2000. 3.7998 5.4133 0.3829 9.5959 5000. 3.9494 5.5792 0.3999 9.9286 10000. 4.0249 5.6566 0.4169 10.0985 20000. 4.0757 5.7071 0.4367 10.2195 50000. 4.1181 5.7454 0.4675 10.3310 100000. 4.1374 5.7614 0.4938 10.3926