Identify the two key factors that determine nuclear stability. Factors determining nuclear stability Answer Bank temperature of the nucleus number of nucleons in the nucleus pressure on the nucleus ratio of neutrons to protons physical state of the element
The Correct Answer and Explanation is:
The two key factors that determine nuclear stability are:
- Ratio of neutrons to protons
- Number of nucleons in the nucleus
Explanation:
Nuclear stability depends on the forces acting within the atomic nucleus. The protons in a nucleus repel each other due to their positive charges, while neutrons provide an attractive strong nuclear force that holds the nucleons together. A delicate balance between these opposing forces governs whether a nucleus is stable or likely to undergo radioactive decay.
1. Ratio of neutrons to protons: This ratio, often referred to as the N/Z ratio (neutron number divided by proton number), is critical to maintaining nuclear stability. In lighter elements, stability is achieved when the number of neutrons and protons is roughly equal. However, as atomic number increases, additional neutrons are needed to mitigate the increasing electrostatic repulsion among protons. A proper balance allows the strong nuclear force to counteract the proton repulsion and hold the nucleus together. If the ratio strays too far from an ideal range, the nucleus becomes unstable. Such nuclei tend to decay by processes like beta decay in order to achieve a more favorable neutron to proton balance.
2. Number of nucleons in the nucleus: The total number of nucleons, which includes both protons and neutrons, also influences stability. As nuclei get larger, especially beyond calcium, the attractive nuclear forces become less efficient at holding all particles together. This is due to the short-range nature of the strong nuclear force. Additionally, more protons mean more repulsion, which must be offset by even more neutrons. There is an upper limit to how many nucleons can exist in a stable configuration. Nuclei with too many nucleons often become unstable and can undergo fission or other forms of decay to break into more stable fragments.
Together, these two factors dictate the stability landscape of all atomic nuclei.
