List two key factors that determine nuclear stabil...

Question

List two key factors that determine nuclear stability.physical state of the elementratio of neutrons to protonsnumber of nucleons in the nucleuspressure of the nucleustemperature of the nucleus

Jules Bruno · Accepted Answer

At the center of an atom, there is a nucleus that is made up of neutrons and protons.A neutron has no net charge. It acts like a ‘glue’ that keeps the nucleus together. This force that holds a nucleus together is called attractive strong forces.A proton has a net positive charge. A proton exerts repulsive Coulombic forces towards other protons since like charges repel.An atom is considered stable when it does not spontaneously emit radiation. In other words, the attractive strong forces overcome the repulsive forces and is able to hold the nucleus together.[readmore]The two key factors that determine nuclear stability are1. Ratio of Neutrons to Protons• The ratio of neutrons to protons in an element predicts the strong attractive forces and the repulsive Coulombic forces.• The greater the number of neutrons, the greater the attractive strong forces. Similarly, the greater the number of protons, the greater the repulsive forces.The Valley or Band of Stabilityrepresents the area where stable, non-radioactive isotopes exist based on their ratio of neutrons to protons. • Atoms not in the band of stability undergo nuclear reactions to become stable.• In general, above the band of stability, atoms undergo beta or neutron emission because there are not enough protons.• Below the band of stability, atoms undergo positron emission or electron capture because there are too many protons.• Atoms with 200 atomic mass unit or more undergo alpha decay or spontaneous fission because there are too many protons and neutronsAtoms with Z ≤ 20 → stable N/Z ratio is 1.0Atoms with Z between 20 to 40 → stable N/Z ratio is 1.25Atoms with Z between 40 to 80 → stable N/Z ratio is 1.50A stable nuclei does not exist for atoms with Z greater than 832. Number of Nucleons in the Nucleus• A nucleon is either a proton or neutron in an atom.• Recall that when considering electrons, elements with 8 valence electrons (i.e. Noble gases) are highly stable because of the completely-filled shells. This observation is called the Octet Rule.• For nucleons, the number of protons or neutrons that make up a completely filled atomic shell is called Magic Numbers• Atoms with a number of protons or neutrons that is considered a magic number is highly stable.• An atom that has both proton and neutron being considered a magic number is observed to be especially stable against decay. These atoms are called Doubly Magic.The magic numbers include:Protons (Z): 2, 8, 20, 28, 50, 82, and 144Neutrons (N): 2, 8, 20, 28, 50, 82, 126, and 184Example:Atom with a Magic Number: Tin which has 50 protons and 69 neutronsDoubly Magic atom: Calcium which has 20 protons and 20 neutronsThe physical state of the element, the pressure of the nucleus, and the temperature of the nucleus have no effect on nuclear stability.

Problem: List two key factors that determine nuclear stability.physical state of the elementratio of neutrons to protonsnumber of nucleons in the nucleuspressure of the nucleustemperature of the nucleus

FREE Expert Solution

Problem Details

Problem: List two key factors that determine nuclear stability.physical state of the elementratio of neutrons to protonsnumber of nucleons in the nucleuspressure of the nucleustemperature of the nucleus

FREE Expert Solution

Problem Details

Sign up for free to watch this video!