The mass of a neutron is approximately equal to the mass of a proton. Selected basis: approximate values.
Bar length measures mass, not physical size. Both bars start at zero kilograms (kg). Pictures identify the objects only.
1.675 × 10⁻²⁷ kg - Mass; measured constant.
A neutron is a type of subatomic particle found in atomic nuclei, carrying no electric charge and playing a key role in holding nuclei together.
A free neutron’s mass. It is a quantum particle with internal structure, not a little solid sphere.
NIST — 2022 CODATA fundamental constants1.673 × 10⁻²⁷ kg - Mass; measured constant.
A proton is a positively charged particle found in the nucleus of atoms, made up of quarks.
Twice the approximately 0.8409 fm charge radius. The charge distribution has no hard boundary; the illustration is schematic.
NIST — 2022 CODATA fundamental constants
There’s always another scale
Fundamental physicsNeutron1.675 × 10⁻²⁷ kgA neutron is a type of subatomic particle found in atomic nuclei, carrying no electric charge and playing a key role in holding nuclei together.
Fundamental physicsProton1.682 fmA proton is a positively charged particle found in the nucleus of atoms, made up of quarks.
Fundamental physicsPlanck length1.616 × 10⁻³⁵ mThe Planck length is a scale formed from fundamental physical constants.
MicroscopicHydrogen atom105.8 pmA hydrogen atom is the simplest neutral atom, with one proton in its nucleus and one electron around it.
MicroscopicDNA double helix2 nmDNA is the molecule that stores hereditary information in living organisms.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?