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37 Cards in this Set
- Front
- Back
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nuclide
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a nucleus with a defined number of protons and neutrons
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radioisotope
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an atom which possesses an unstable
nucleus called a radionuclide. |
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radionuclide
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an unstable nucleus
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radioactive decay
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what an unstable nucleus will go under to transform into a more stable nucleus
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radioactivity
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produced when a nucleus undergoes radioactive decay
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Although many nuclei are stable,
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most known nuclei are unstable and spontaneously emit
radiation. |
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The strong nuclear force is a force of
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attraction
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The electromagnetic force is a force of
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repulsion
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only protons repel one another by electric force
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the heavier the nucleus,
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the more neutrons required for stability
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Any nuclide outside the belt of stability is
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unstable
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radioactive elements
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all nuclides of the elements with atomic numbers higher than 83
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Nuclei with even numbers of both protons and neutrons
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are more stable than those with odd numbers of
neutron and protons |
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An unstable nucleus
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can spontaneously change or “decay” into a stable nucleus by ejecting particles of matter and excess energy
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3 forms of radioactivity
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-alpha particles
-beta particles -gamma rays All three forms originate from changes that occur within an unstable nucleus |
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alpha particles
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mass of 4 and charge of +2
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beta particles
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small mass and charge of -1
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gamma rays
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no mass and no charge
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alpha particle
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a particle with the same composition as a Helium molecule; 2 protons and 2 neutrons
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When an alpha particle is emitted by a nucleus, the
unstable nuclide is transformed into a new nuclide of a different element with a lower mass number and a lower atomic number. |
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Conserve mass number (A)
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The sum of protons plus neutrons in the products must
equal the sum of protons plus neutrons in the reactants. |
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Conserve atomic number (Z) or nuclear charge
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The sum of nuclear charges in the products must equal
the sum of nuclear charges in the reactants. |
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alpha decay
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mass number (A) is conserved
mass number (Z) is conserved *Because the nuclide loses 2 protons, it changes identity |
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beta partcile
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a fast moving electron that is ejected from the nucleus by the conversion of a neutron into a proton.
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When a beta particle is emitted by a nucleus, the nuclide
is transmuted into a new nuclide of a different element with the same mass number and a larger atomic number. |
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gamma radiation
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-has no mass or charge
-consists of high energy photons that are released from excited nuclei, most often in parallel with particle emission |
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The penetrating power of radiation
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a function of mass, with gamma rays being the least massive and most energetic
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Positron emission
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involves the release of a positron when a proton is changed into a neutron.
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positron
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a particle like an electron but with a positive charge.
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Electron capture
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process in which an inner electron is captured by a proton in the nucleus to form a neutron
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Nuclides outside band of stability are often radioactive
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radioactive decay series
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a series of radioactive decays beginning with a heavy nuclide and ending with a non reactive one
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natural decay
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a radionuclide emits radioactivity in the form of energy or small particles
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electron capture
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a neutron poor radionuclide absorbs an electron, which causes a proton to become a neutron
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bombardment (induced)
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the production of nuclides
by the bombardment of nuclei with small particles |
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fission
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natural or artificial production of two smaller daughter nuclides from one large nuclide, accompanied by the release of energy and more neutrons
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fusion
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the production of a larger nuclide from the combination of two smaller nuclei
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