Input interpretation
period 1 elements | van der Waals radius
Results
hydrogen | 120 pm (picometers) helium | 140 pm (picometers)
period 1 elements | van der Waals radius | 130 pm (picometers) (median)
Relative values
| visual | ratios | | comparisons hydrogen | | 0.86 | 1 | 14% smaller helium | | 1 | 1.17 | 17% larger
Plot
Plot
Periodic table location
Periodic table location
Atomic radii properties
| hydrogen | helium atomic radius (empirical) | 25 pm | atomic radius (calculated) | 53 pm | 31 pm covalent radius | 31 pm | 28 pm van der Waals radius | 120 pm | 140 pm
Units
Unit conversions for median van der Waals radius 130 pm
0.13 nm (nanometers)
1.3×10^-10 meters
5.12×10^-9 inches
1.3 Å (ångströms)
Comparisons for median van der Waals radius 130 pm
≈ 4.2 × atomic radius of helium (the smallest atom) ( ≈ 31 pm )
≈ 5.2 × atomic radius of hydrogen ( ≈ 25 pm )