Nucleus

E_c (calculation)/MeV

E_c (formula of thumb)/MeV

R_l/mm

X₀/g·cm⁻²

Al

42.6230

42.837

89.924

24.27948

Fe

22.4367

22.3935

17.9550

14.13058

Cu

20.0623

20.1720

14.7577

13.16387

Pb

8.0216

7.3282

5.5602

6.30527

W

7.9613

8.1074

3.5151

6.76657

Au

7.5892

7.6022

3.3263

6.42641

Water

48.04

48.426

360.80

360.80