Atomic nucleus
An atomic nucleus is the compact central part of an atom, made from protons and neutrons.
10 fmCharacteristic sizeBeyond the eye
Atomic nucleus 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 sizeHydrogen atom has about 10,600 times the characteristic size of Atomic nucleus.
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Atomic nucleus10 fmCharacteristic size
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Hydrogen atom105.8 pmCharacteristic size
Inset ×4,390Atomic nucleus is too small to see clearly at this scale. The ring marks its position; only the inset is enlarged.
Measurements, assumptions & sources +
Atomic nucleus
A 10 fm diameter scale model of a heavy nucleus. Nuclear size depends on the number of nucleons.
University of Utah — Cell size and scale
The marked characteristic size 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 characteristic size with characteristic size. The records below preserve each value’s basis and caveats.
Atomic nucleus
10 fmCharacteristic size · representative
A 10 fm diameter scale model of a heavy nucleus. Nuclear size depends on the number of nucleons.
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
- Characteristic size ↔ Characteristic size
- Relative size
- Hydrogen atom is larger on this measurement by a factor of about 10,600.
How to read the visual
The labelled spans and stored measurements determine the scale; unmeasured illustration details do not.
- Atomic nucleus is labelled representative; 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.
MicroscopicAtomic nucleus10 fmAn atomic nucleus is the compact central part of an atom, made from protons and neutrons.MicroscopicHydrogen atom105.8 pmA hydrogen atom is the simplest neutral atom, with one proton in its nucleus and one electron around it.
Fundamental physicsProton1.682 fmA proton is a positively charged particle found in the nucleus of atoms, made up of quarks.
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.
