Concept:Nuclear stability is determined by the balance between neutrons and protons within the atomic nucleus.
Explanation:The nucleus of an atom contains positively charged protons and neutral neutrons.
Protons repel one another because they carry the same positive charge.
Neutrons help reduce this electrostatic repulsion by increasing the distance between protons.
Hence, the stability of a nucleus is measured by its neutron-to-proton ratio, expressed as
pn.
For light elements with atomic number below 20, a stable nucleus usually possesses a neutron-to-proton ratio of approximately
1:1.
As the atomic number increases, more neutrons are needed to overcome the stronger proton repulsion, so the ratio exceeds
1:1.
Thus, the neutron-to-proton ratio is the key factor that determines nuclear stability.
Among the given options, the correct ratio is neutrons to protons.
Answer:B. Neutron/proton