Nuclear Properties Flashcards
What experiment led to the discovery of the nucleus?
The Geiger-Marsden experiment in 1909 involved scattering alpha particles off a thin gold foil. Ernest Rutherford and his colleagues observed that some alpha particles were deflected at large angles, which contradicted the prevailing “plum pudding” model of the atom and led to the discovery of the atomic nucleus.
Explain the concept of parity in nuclear physics.
Parity refers to the symmetry of a physical system under spatial inversion, where all spatial coordinates are reflected through the origin. Parity conservation implies that the fundamental laws of physics remain unchanged under such transformations, except for interactions involving the weak nuclear force, which violate parity conservation.
What is the relationship between the magnetic moment and the angular momentum of a particle?
In quantum mechanics, the observable magnetic moment of a particle is proportional to its angular momentum. For particles with spin, the magnetic moment can be expressed as the product of the spin g-factor, the magnitude of the spin, and the nuclear magneton.
Describe the properties of a proton.
Protons are subatomic particles with a positive electric charge, a mass of approximately
1.672621637 ×10−27 kg, and a spin of 1/2
. They have even parity, a charge radius of 0.877 femtometers, and a g-factor of 5.5856912. Protons are extremely stable and can transform into neutrons via beta decay or electron capture within the nucleus.
How was the neutron discovered, and what are its properties?
The neutron was discovered by James Chadwick in 1932 through experiments involving the bombardment of beryllium with alpha particles. Neutrons are subatomic particles with no electric charge, a mass of approximately
1.67492729 ×10−27 kg, and a spin of 1/2. They have even parity and a g-factor of −3.8260837. Unlike protons, free neutrons are unstable and decay into a proton, an electron, and an antineutrino via beta decay.
What are anti-particles, and how do they differ from their corresponding particles?
Anti-particles are particles that have the same mass as their corresponding particles but opposite electric charge and magnetic moment. They can only be created or destroyed in pairs with their corresponding particles. Anti-particles play a crucial role in particle physics and are involved in processes such as pair production and annihilation.
