Nuclear Reactions Flashcards
Binding energy
The amount of energy required to break up a given nucleus into its constituent protons and neutrons
E=mc^2
Mass defect
The mass of the constituent protons and neutrons is larger than the original mass of a nucleus
Result of matter converted to energy
Isotopic notation
Subscript Z (atomic number = # of protons) Superscript A (mass number = protons + neutrons)
Radionucleotide
Any radioactive isotope, especially those used in nuclear medicine
Radioactivity
When the nucleus of an atom is unstable and spontaneously emits particles or electromagnetic radiation
Fusion
When small nuclei combine into a large nucleus resulting in great amounts of energy
Fission
A large, heavy (A > 200) atom splits to form smaller, more stable nuclei and neutrons
Release large amount of energy since original nucleus is more unstable
Absorption of low-energy neutron induces fission
Chain reaction
Fission reactions that release more neutrons to cause other atoms to undergo fission
Nucleon/Baryon number conservation
The total number of neutrons plus protons remains the same
Radioactive decay
Type of fission reaction
Spontaneous decay of certain nuclei accompanied by emission of specific particles
Alpha decay
The emission of an a-particle = He nucleus with 2 protons and 2 neutrons
Does not penetrate shielding
Z’ = Z - 2
A’ = Z - 4
Beta decay
The emission of a B-particle which could be a B- (electron) or B+ (positron)
B- decay
A neutron is consumed and a proton takes its place
Neutron decays into a proton and a B- particle (antineutrino)
Z’ = Z + 1
A’ = A
B+ decay
A proton is consumed and a neutron takes its place
A proton decays into a neutron and a B+ particle (neutrino)
Z’ = Z - 1
A’ = A
Gamma decay
The emission of gamma-particles, which are high-energy photons
Usually follows another type of nuclear decays and is a way for the nucleus to shed excess energy
Z’ = Z
A’ = A
