Nuclear Physics Flashcards
Describe Rutherford’s Gold Foil Experiment.
Alpha radiation is shone to a piece of gold foil. These observations were observed.
Most particles moved through completely unaffected - Most of the atom was empty space.
Some were slightly deflected - Experienced an electrostatic force, meaning that there is a positive charge in the nucleus
1/10000 were deflected more than 90 degrees - The nucleus is extremely small and contained most of the mass.
Formula to calculate Nuclear Radius
R = R0A^1/3
Define Decay Constant
? The probability of a single radioactive nuclei decaying at any one time
Define Half-life of an isotope
? The average time taken for the mass of an isotope to reduce to half of its original mass.
The activity of an isotope
? Number of nuclei of that isotope that decays per second.
Units: Becquerel (Bq)
Properties and uses of alpha radiation
2 protons, 2 neutrons. Strongly ionising. 3-7cm range in air and stopped by a thin sheet of paper. Deflected in a magnetic field.
Used in smoke detection.
Properties and uses of beta radiation
Electron. Mildly ionising. 20cm - 3m range in air, absorbed by aluminum. Deflected in the magnetic field (opposite direction). Used in thickness monitors.
Properties and uses of gamma radiation
In the form of electromagnetic radiation, high energy photons. At least 1km range in air, significantly absorbed by lead. Weakly ionising, unaffected by the magnetic field.
Used to sterilise medical equipment and kill cancer cells as well as medical tracer.
Safe use of radiation
- Never directly handle the source
- Use long-armed tongs
- Display signage warnings
- Limit the time of using the radiation
- Store it in an appropriate lead box.
Background radiation
Radon Gas, Rocks, Cosmic Radiation, Nuclear weapon, Nuclear disasters.
Radioactive decay
A random process in which the nucleus decay, is unpredictable and determined by chance.
