The characteristic size of a hydrogen atom is about 10,600 times the characteristic size of an atomic nucleus. Selected basis: a representative value for Atomic nucleus; a representative value for Hydrogen atom; approximate values.
The ring marks the true-scale position of an atomic nucleus; it does not show its width. Only the inset is enlarged (×4,020).
Both rulers start at the same zero and share one linear scale. Artwork keeps its original proportions.
10 fm - Characteristic size; representative.
An atomic nucleus is the compact central part of an atom, made from protons and neutrons. Nearly all of an atom’s mass is concentrated there.
A 10 fm diameter scale model of a heavy nucleus. Nuclear size depends on the number of nucleons.
University of Utah — Cell size and scale105.8 pm - Characteristic size; representative.
A hydrogen atom is the simplest neutral atom, with one proton in its nucleus and one electron around it.
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
There’s always another scale
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.
MicroscopicCell10 µmA cell is the basic structural unit of living organisms.
PeopleHair70 µmA hair is a slender strand of protein that grows from the skin of humans and other mammals.Side by side
Illustrative artwork · not to scale
Illustrative artwork · not to scale
Illustrative artwork · not to scale
Illustrative artwork · not to scaleGot a good eye for scale?