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Nuclear density
Intermediate
Roughly 10¹⁷ kg/m³, constant across nuclei.
About 2.3×10¹⁷ kg/m³ and nearly the same for all nuclei; a matchbox-sized lump of nuclear matter would weigh billions of tonnes.
Neutron star matter has this density.
Atoms are mostly empty, nuclei are not.
In more detail
Nuclear density is roughly constant across nuclei, about 2.3 × 10¹⁷ kg per cubic metre. This is because the strong force saturates, so nucleons are packed at a fixed density.
Real-world uses
- Neutron stars approach nuclear density.
- Nuclear models use constant density to estimate sizes.
- Physicists note that nuclear matter is extremely dense, which is why neutron stars are so compact.
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Frequently asked questions
How dense is that?
Enormous, about the mass of a mountain in a teaspoon.
Why is it constant?
The nuclear force is short-range and saturates, so nucleons only interact with near neighbours.
Why is nuclear density nearly the same for all nuclei?
The strong force saturates, so each nucleon interacts mainly with its neighbours, giving a constant density.
Related topics in Atomic & Nuclear Physics
Nucleus composition · Isotopes, isobars, isotones · Nuclear size · Mass defect · Binding energy · Binding energy per nucleon