Proton
A proton is a positively charged particle found in the nucleus of atoms, made up of quarks.
1.682 fmDiameterBeyond the eye
Proton vs Hydrogen atom
What are they, and what does the difference actually look like?
Two things. One honest scale.
Meet the pair
What these two things are
Hydrogen atom
A hydrogen atom is the simplest neutral atom, with one proton in its nucleus and one electron around it.
105.8 pmCharacteristic sizeThe characteristic size of Hydrogen atom is about 62,900 times the diameter of Proton.
01
Proton1.682 fmDiameter
02
Hydrogen atom105.8 pmCharacteristic size
Inset ×26,100Proton is too small to see clearly at this scale. The ring marks its position; only the inset is enlarged.
Measurements, assumptions & sources +
Proton
Twice the approximately 0.8409 fm charge radius. The charge distribution has no hard boundary; the illustration is schematic.
NIST — 2022 CODATA fundamental constants
The marked diameter is calibrated. Unmeasured illustration details are representative.
Hydrogen atom
A diameter of twice the Bohr radius, used as a characteristic scale. An electron cloud has no hard outer surface.
NIST — 2022 CODATA fundamental constants
The marked characteristic size is calibrated. Unmeasured illustration details are representative.
Change the comparison
Put something else beside it.
Measurement details
Why these numbers?
The visual compares diameter with characteristic size. The records below preserve each value’s basis and caveats.
Proton
1.682 fmDiameter · measured constant
Twice the approximately 0.8409 fm charge radius. The charge distribution has no hard boundary; the illustration is schematic.
Hydrogen atom
105.8 pmCharacteristic size · representative
A diameter of twice the Bohr radius, used as a characteristic scale. An electron cloud has no hard outer surface.
- Comparing
- Diameter ↔ Characteristic size
- Relative size
- Hydrogen atom is larger on this measurement by a factor of about 62,900.
How to read the visual
The labelled spans and stored measurements determine the scale; unmeasured illustration details do not.
- Proton is labelled measured constant; treat the displayed value as a comparison anchor rather than false precision.
- Hydrogen atom is labelled representative; treat the displayed value as a comparison anchor rather than false precision.
There’s always another scale
Follow your curiosity.
Fundamental physicsProton1.682 fmA proton is a positively charged particle found in the nucleus of atoms, made up of quarks.MicroscopicHydrogen atom105.8 pmA hydrogen atom is the simplest neutral atom, with one proton in its nucleus and one electron around it.
Fundamental physicsPlanck length1.616 × 10⁻³⁵ mThe Planck length is a scale formed from fundamental physical constants.
MicroscopicDNA double helix2 nmDNA is the molecule that stores hereditary information in living organisms.
Microscopic10 µm cell10 µmA cell is the basic structural unit of living organisms.
People70 µm hair70 µmA hair is a slender strand of protein that grows from the skin of humans and other mammals.Side by side
Another point of view.
