Nuclear Chem Flashcards
Atomic Number
Number of Protons
Ions
When atom loses or gains one or more electron and net electrical charge changes
Isotopes
elements with same # of protons but different # of neutrons
atomic mass unit (amu)
roughly defined as weight of either proton or neutron
alpha radiation
two protons and two neutrons are released from atom
beta radiation
when electron is released from nucleus
positron emission
when proton and electron form neutron and positron
positron is particle with mass identical to electron but with positive charge
gamma radiation
very energetic form of light energy is released; no mass
rate formula
rate=kN
determining mass loss to decay
ln(Nt/No)=-kt
rate constant formula
k=.693 / (t1/2)
SI unit for rate of decay
Becquerel (Bq)
Strong Nuclear Force
what holds protons together
Atom Stability if…
first 20 elements, # of protons/neutrons are same
after first 20, elements need more protons than neutrons
nothing stable after 83
Too many neutrons (above belt)
undergo Beta Radiations
Above 83amu
undergo alpha radiation
too many protons (below belt)
undergo positron radiation
Radioactive Series
unstable nuclei require multiple emissions to become more stable
Formula for Energy Involvment in Nuclues
E=mc2
To find energy produced in reaction:
- ) find difference in mass (Kg) between reactants and products
- ) Use E=mc2 to find ammount energy produced
Mass Defect
all nuclei have smaller mass than sum of subatomic particles masses
To find Nuclear Binding Energy
- ) find difference in mass (Kg) between nucleus and sum of protons/neutrons
- ) Use E=mc2 to find energy from mass lost
Transmutation
change in nucleus of atom because it has been struck by subatomic particle (mainly neutrons)
Nuclear Fission
splitting and releasing energy
