chapter 30 Flashcards
The binding energy of a nucleus is the amount of energy needed to __________.
disassemble the nucleus
For two nucleons 2 fm apart, the strong force is __________.
equally strong for any combination of protons and neutrons
what is the atomic number Z
the number of protons
what is N?
the number of neutrons
what is binding energy
the energy needed to break nuclear bonds and disperse nucleons
When are nuclei stable
when the number of protons (Z) is less than 16 and N=Z
what is fusion energy
when two ligt nuclei are fused together to make a single stable larger nucleus, the final nucleus will have higher bidning energy (lower mass per nucelo) and energy is released in the nuclear fusion process
what is fission energy
Nuclei with A>60 become less stable as their mass increases and break into fragments that are lighter
what is the mass number with the most tightly bound nucleis with the lowest mass per nucleon and highest binding energy per nucleon
56, iron
what defines alpha decay
the parent nuclei reduces its atomic mass by 4 nucleon, so it loses 2 protons and 2 neutrons
what defines Beta minus decay
the atomic number stays the same but the proton count increases by one as a negative electron is ejected
what defines beta plus decay
a proton turns into a neutron and emits a positron e+ which is the antiparticle of the electron
when does gamma decay occur
it occurs when a proton or neutron undergoes a quantum jump between energy levels without changing Z or N
what is a decay series
a series of decays that occur until a nuclei reaches the most stable state
