Balancing Nuclear Equations # = (1) + ____ = (0) + ____ Atomic number 39 is yttrium, Y Y
Alpha Decay Alpha production ( ): an alpha particle is a helium nucleus Alpha decay is limited to heavy, radioactive nuclei
Alpha Radiation Limited to VERY large nucleii.
Beta Decay Beta production ( ): A beta particle is an electron ejected from the nucleus Beta emission converts a neutron to a proton
Beta Radiation Converts a neutron into a proton.
Gamma Ray Production Gamma ray production ( ): Gamma rays are high energy photons produced in association with other forms of decay. Gamma rays are massless and do not, by themselves, change the nucleus
Deflection of Decay Particles Opposite charges_________ each other. Like charges_________ each other. attract repel
Positron Production Positron emission: Positrons are the anti-particle of the electron Positron emission converts a proton to a neutron
Electron Capture Electron capture: (inner-orbital electron is captured by the nucleus) Electron capture converts a proton to a neutron
Types of Radiation
Nuclear Stability Decay will occur in such a way as to return a nucleus to the band (line) of stability. The most stable nuclide is Iron-56 If Z > 83, the nuclide is radioactive
A Decay Series A radioactive nucleus reaches a stable state by a series of steps
Decay Kinetics Decay occurs by first order kinetics (the rate of decay is proportional to the number of nuclides present) N = number of nuclides remaining at time t N 0 = number of nuclides present initially k = rate constant t = elapsed time
Calculating Half-life t 1/2 = Half-life (units dependent on rate constant, k )
Nuclear Fission and Fusion Fusion: Combining two light nuclei to form a heavier, more stable nucleus. Fission: Splitting a heavy nucleus into two nuclei with smaller mass numbers.
Energy and Mass Nuclear changes occur with small but measurable losses of mass. The lost mass is called the mass defect, and is converted to energy according to Einsteins equation: E = mc 2 E = mc 2 m = mass defect m = mass defect E = change in energy E = change in energy c = speed of light c = speed of light Because c 2 is so large, even small amounts of mass are converted to enormous amount of energy.
Fission Processes A self-sustaining fission process is called a chain reaction.