Mrs Roberts: What do you think you're made of? Mr Spellman: Big question. Grit, determination, hard-working, handsome, charming, funny. Mrs Roberts: Well, I guess. But you're actually made of atoms.

Scientists have long wondered whether there is a limit to the number of protons and neutrons that can be clustered together to form the nucleus of an atom. A new study comes closer than ever to ...

For most atomic nuclei, the maximum number of neutrons that can be bound is unknown. The discovery of two neutron-rich nuclei — and the confirmed absence of others — might help solve this conundrum.