Plutonium-244 Nucleus size and scale context

The plutonium-244 nucleus is the heavy atomic nucleus of a long-lived plutonium isotope, built from 94 protons and 150 neutrons. It was forged in rare neutron-rich explosions before the Solar System formed, and its 81.3-million-year half-life made it an important extinct radionuclide in early Solar System history. Read its scale context, comparisons, and journey links on the canonical object page.

ProtonBaryon·1.68 fm

NeutronBaryon·~1.72 fm

Plutonium-244 NucleusAtomic nucleus·15 fm

Hydrogen AtomAtom·100 pm

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Particles

Neutron

The neutron is the electrically neutral baryon that, together with the proton, builds atomic nuclei. A free neutron decays by beta-minus decay into a proton, an electron, and an electron antineutrino in about 15 minutes, while neutron-rich matter can persist inside neutron stars.

Scale fact~1.72 fmdiameter

Object class: Baryon

Particles

Plutonium-244 Nucleus

Scale fact15 fmdiameter

Object class: Atomic nucleus
Composition: 94 protons, 150 neutrons

Atoms

Hydrogen Atom

Hydrogen is the universe’s simplest and most common atom. Most hydrogen nuclei were forged in the first minutes after the Big Bang, and neutral hydrogen atoms emerged only after the universe cooled enough for electrons and protons to combine about 380,000 years later.

Scale fact100 pmdiameter

Object class: Atom
Composition: 1 proton, 1 electron