Size of the nucleus was measured by Lord Rutherford using the scattering patterns of alpha particles passing through a gold foil. It is 10-15 m.
Generalic, Eni. "Size of the nucleus." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
Glossary
Periodic Table