Question

Don't write in cursive and explain everything in your answer as you would to someone totally new to the subject.

Answer 1

The neutron-proton ratio (N/P ratio) of an atomic nucleus influences the stability of the nucleus. The nuclei having more number of protons (insufficient number of neutrons) are less stable. This is because like charges repel each other. However, a strong force of attraction, called the strong nuclear force, exists between nucleons (neutrons and protons). Neutrons are well involved in this attractive force. The more protons packed in the nucleus, the more neutrons are required to bind the nucleus together. Stable nuclei with low atomic numbers (up to about 20) have nearly equal numbers of neutrons and protons. For nuclei with higher atomic numbers, the number of neutrons exceeds the number of protons. As the atomic number increases, the repulsion between the protons becomes more. Hence, the large nuclei need to have more and more neutrons in it in order to balance out the increased distance (to reduce repulsions) between the protons These proton-rich (insufficient number of neutrons) nuclei can increase their ratio by either positron emission or electron capture. Both kinds of decay increase the number of neutrons and decrease the number of protons. Positron emission is more common than electron capture among the lighter nuclei. But, electron capture becomes more common as nuclear charge increases. Alpha decay is observed in neutron-poor nuclie that have atomic numbers larger than 83 which involve a slight increase in n/p ratio "B++:e (positron emission) 133I + e- Te (electron capture)