Nuclear structure stability is determined by the binding energy between protons and neutrons in the nucleus. There are several factors that contribute to nuclear stability including the ratio of protons to neutrons, binding energy per nucleon, and nuclear shell structure. Understanding nuclear stability is important for applications in nuclear power generation, nuclear medicine, nuclear astrophysics, and material science.

1. Nuclear Structure Stability
Muqadass Tahir (L1F20BSPH0033)

2. Start
Building blocks of atoms: protons, neutrons, electrons
Classification in the basses of Atomic Mass than Atomic
Number for a better understanding
Different Isotopes, isobars, and isotones were classified to
understand the stability of the overall system

3. Nuclear Models
 Liquid drop model
 Shell model
 Nuclear forces

4. Binding energy (Achieving Stability)
Einstein's mass–energy equation E = mc2
 The distance at which the attraction caused by the strong
nuclear force can win over the electromagnetic force,
repelling protons. (1-2 fm)
 Calculation of Mass-defect

5. Stability in Higher Elements (>82)
 Radioactive decay processes: alpha decay, beta decay,
gamma decay acts as Stability Processes

6. Half-Life
 These achievements gave
the idea of half-life of
Nucleus which solved the
1807 astonishing discovery
of radioactive decay after a
century.

7. Stability of Nucleus
Muhammad Ahmad
(L1F20BSPH0040)

8. Binding energy / Nucleon
 The ratio of a
nucleus's binding
energy to the number
of nucleons in that
nucleus

9. Example
7.6 Mev

10. N/P ratio
 The ratio of neutrons to protons in a
nucleus determines its stability
1:1
(>20)
 Valley of Stability

11. The concept of
Magic Numbers
 number of nucleons that are
arranged into complete shells
within the atomic nucleus (2, 8,
20, 28, 50, 82, 126)
K = 2, L = 8, M = 18, N =
32

12. Radiations
 Alpha , Beta , Gamma , Electron Capture

13. Parity of
Nucleus
Sana Quershi (L1F20BSPH0027)

14. In QM
 every moving particle has a wave associated with it
 Parity of nucleus refers to the behavior of w ( psi ) as a result
of inversion of coordinates

15. Definition
 Parity is a symmetry property of nuclei that reflects their
behavior under mirror reflection
Parity is given (-1)l
 l is the angular momentum of the nucleon

16. Odd & Even
w ( x, y, z ) = w ( x, y, z) w ( x, y, z ) = - w ( x, y, z )

17. Conservation of Parity
 Parity conservation is a principle in physics that states that two mirror
images of each other should act the same
 left-spinning and right-spinning particles should act the same

18. Violation (Wu Experiment)
 1956 by the Chinese American physicist Chien-
Shiung Wu
 the mirror image of the decay is different from the
actual decay
 This result violated the law of conservation of Parity
The interaction between the spin-up and spin-
down protons and neutrons in a nucleus
makes it hold more tightly.

19. Applications
Abdulhannan Mirza (L1F20BSPH0016)

20. Power Plants
 Nuclear stability is crucial for the
development and operation of nuclear
power plants. The stability of radioactive
isotopes determines their suitability for
use as nuclear fuel, ensuring sustained
energy production while minimizing the
risk of accidents.

21. Medicine
 Nuclear medicine, the stability of radioisotopes is essential for diagnostic and
therapeutic applications.
 Radioactive isotopes with specific decay rates and radiation emissions are
used for medical imaging, such as PET scans
 cancer treatment

22. Nuclear
Astrophysics
 Nuclear stability plays a critical role in
understanding the processes that power
stars and the formation of heavy
elements in the universe
 The stability of nuclei governs nuclear
fusion reactions that occur in stars, and
knowledge of these processes is
essential for modeling stellar evolution
and nucleosynthesis

23. Material Science
 Nuclear stability has implications for material science, particularly in the development of
advanced materials with tailored properties.
 Understanding the relationship between nuclear stability and material properties can lead to
the creation of new materials with enhanced radiation resistance and other desirable
properties.