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37 Cards in this Set
- Front
- Back
Wilhelm Roentgen
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discovered X-rays. 1895
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Henri Becquerel
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phosphorescence won nobel peace prize. Used element salts
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phophoscence
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minerals that emit light after being exposed to sunlight
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pitchblende
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Becquerel's mineral sample
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Marie & Pierre Currie
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"defined" radioactivity
discovered: polonium radium Won Nobel Peace Prize |
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Radiation
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the rays and particles given off by radioactivity
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isotopes
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atoms of the smae element tht have different numbers of neutrons
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radioisotopes
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atoms with unstable nuclei
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Ernest Rutherford
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Gold foil experiment
Identified: alpha radiation beta radiation gamma radiation |
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neucleons
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postitive charged protons and neutral neutrons
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strong nuclear force
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force that acts only on subatonic particles that are close together & overcomes the electrostatic repulsions between protons.
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type of radioactive decay depends on it's stability. Explain....
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Atoms above the line of stability have too many neutrons to be stable
Below the line-too many protons to be stable |
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band of stability
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area on graph where all stable nuclei are found
see page 811 for graph |
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beta decay
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above the line
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alpha decay
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more than 83 protons. It decays spontaneously
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postitron emission
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a radioactive decay process that involves the emission of a postitron from a nucleus
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positron
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particle with same mass as an electron but opposite charge
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positron symbol
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O
1 |
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electron capture
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occurs when nucleus of atom draws in a surrouning electron
(Usually from the lowest energy level) |
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radioactive decay series
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a series of nuclear reactions that starts with an unstable nucleus & results in the formation of a stable nucleus.
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transmutation
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conversion of an atom of 1 element to an atom of another element
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induced transimulation
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process which involves striking nuclei with high velocity charged particles
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transuranium elements
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elements immediately after uranium on periodic table. elements with atomic #93 & higher. All are radioactive
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half-life
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the time required for 1/2 of a radioisotope's nuclei to decay into its product
Know how to figure (page 817) |
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radioactive decay rates are measured in.........
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half-lifes
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radiochemical dating
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process of determining the age of an object by measureing amount of certain radioisotopes remaining in that object.
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mass defect
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difference in mass between a mucleus & its component nucleons
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critical mass
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sample that is massive enough to sustain a chain reaction
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subcritical mass
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chain reaction stops because neutrons escape- no fissions
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supercritical mass
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chain reaction speeds up because neutrons cause more fissions
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breeder reactors
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reactors that produce more fuel than they use
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nuclear fusion
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The combining of atomic nuclei
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theronuclear reactions
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fusion reactions
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ionizing radiation
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radiation energetic enough to ionize matter that it collides with
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radiotracer
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radioisotope that puts out non-ionizing radiation used to detect a specific element
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nuclear fission
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splits large nuclei into smaller pieces
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nuclear fusion
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put smaller nuclear into larger ones
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