Input interpretation
period 1 elements | nuclear radius
Results
hydrogen | 1.2 fm (femtometers) helium | 1.512 fm (femtometers)
period 1 elements | nuclear radius | 1.356 fm (femtometers) (median)
Relative values
| visual | ratios | | comparisons hydrogen | | 0.7937 | 1 | 20.63% smaller helium | | 1 | 1.26 | 25.99% larger
Unit conversions for median nuclear radius 1.356 fm
1.356×10^-15 meters
5.338×10^-14 inches
Comparisons for median nuclear radius 1.356 fm
≈ 0.48 × classical electron radius ( ≈ 2.8×10^-15 m )
≈ 1.6 × proton root-mean-square charge radius ( ≈ 8.4×10^-16 m )