8. What is “radioactivity”?
• Emissions
o Not affected by temperature
o Could change color of glass
o Burn skin
o Create heat
• Rutherford and Soddy (1908)
o TRANSMUTATION of one element to another
• The atom is not an indestructible unit!
9. Types of Radiation
• Non-ionizing (low energy)
o Low frequency
• Ionizing (high energy)
o High frequency
• Activity!
o Label where you think non-ionizing and ionizing radiation are in
the spectrum
o categorize
On Dec. delivered prelim paper on xraysThe Term x-ray, x for an unknownCaused a great stir, may have been ignored had it not been for the xrays of his hands which took 3-10 mins to acquire. He produced evidence!1st physics nobel prize
Believed that salts could emit penetrating x-ray like radiation when illuminated by bright sunlight.Phosphorescence-absorption of radiation, continues after radiation has stoppedInherited the salts from his father Uranium salts phosphoresce in prescence of lightUranium gave off radiation all by itselfImage of photographic plate fogged by exposure to radiation from uranium salt
Pierre suggested Marie do research from BecquerelCoined the name RadioactivitySubstance disappeared spontaneously reducing itself to one half in a certain timeUraninite (pitcheblende)Radium and calcium are bone seekersAplastric anemia – disease of the blood caused by defective function of the blood forming organs (bone marrow)Lab notebooks strongly contaminatedCookbooks are home were radioactive 50 years after her death (ask why they think it was still radioactive)
Radioactive tracer is added to a substance so it can be detected later. Can locate tumors, function of organs.
All radioactive elements decay with a specific half-lifeMake sure to mention that there are super high energy aka ionizing
It was the discovery and investigation of the phenomenon of radioactivity that led to our present understanding of the basic structure of the atom.
Nuclear fission is used to generate electricity as an alternative energy source.Fissions-spliting of nucleiFusion-combining 2 nuclei
The fission of an atom of uranium produces 10 million times the energy produced by the combustion of an atom of carbon from coal.