Light elements with Z

Question

Light elements with Z < 20 generally have a neutron/proton ratio about equal to ________

Quizplus · Accepted Answer

For light elements with low atomic number (Z < 20), the neutron/proton ratio is roughly equal to 1:1, as the stability of the nucleus is primarily determined by balancing the strong nuclear force with the electrostatic repulsion between protons. As the atomic number increases beyond 20, the neutron/proton ratio tends to increase to help overcome the increasing electrostatic repulsion between the protons in the nucleus.

Light Elements with Z < 20 Generally Have a Neutron/proton