How heavy is an atom's nucleus?
A single teaspoon of atomic nuclei would weigh as much as 900 Great Pyramids of Giza.
Atoms are mostly empty space, with nearly all their mass concentrated in an incredibly tiny nucleus—about a trillion times smaller than the atom itself. This extreme density means that a teaspoon of pure nuclear matter would weigh approximately 5 billion tons.
Nerd Mode
The density of an atomic nucleus is approximately 2.3 × 10^17 kilograms per cubic meter. For context, the Great Pyramid of Giza weighs roughly 6 million tons. A single teaspoon of nuclear matter, with a volume of about 5 milliliters, would weigh 5.5 billion tons—equivalent to approximately 900 Great Pyramids or the entire human population many times over.This extraordinary density exists because the nucleus contains nearly all of an atom's mass in the form of protons and neutrons, packed tightly together by the strong nuclear force. Meanwhile, electrons orbit at a vast distance from the nucleus. If an atom were enlarged to the size of a football stadium, the nucleus would be no larger than a small marble at the center.If you could somehow collect a teaspoon of this material, it would not remain on Earth's surface. Its density far exceeds that of surrounding rock, so it would immediately punch through the crust and continue sinking until reaching Earth's core. Such extreme density occurs naturally only in neutron stars—the collapsed remnants of massive stars following a supernova.
Verified Fact
FP-0003231 · Feb 17, 2026