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