Suppose that a new element called “unobtainium” is discovered to have 120 protons and 200 neutrons. What is the neutron-to-proton ratio of this element, and what percent larger is the volume of this...

Suppose that a new element called “unobtainium” is discovered to have 120 protons and 200 neutrons. What is the neutron-to-proton ratio of this element, and what percent larger is the volume of this nucleus than the volume of the U-238 nucleus?