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the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay
Isotope with an unstable nucleus that becomes more stable by spontaneously emitting energy and particles.
(physics) the change of one chemical element into another (as by nuclear decay or radioactive bombardment)
A type of nuclear radiation consisting of two protons and two neutrons
- Symbol: a or He
- Notation: 4/2a (or 4/2 He)
- Mass: 4 amu
- Charge: 4+
-Penetrating power: Low (Paper)
An electron emitted from the nucleus during some kinds of radioactive decay
- Symbol: B-
- Notation: 0/1B
- Mass: 0 amu
- Charge: -1
-Penetrating Power: Moderate (Metal Foil)
A particle with the mass of an electron but a positive charge
- Symbol: B+
- Notation: 0/1 B+ or 0/1 e
- Mass: 0
- Charge: +1
- Penetrating Power: Moderate (Metal Foil)
Electromagnetic waves with the shortest wavelengths and highest frequencies, electromagnetic radiation emitted during radioactive decay and having an extremely short wavelength
- Symbol: Y
- Notation: 0/0 Y
- Mass: 0 amu
- Charge: 0
- Penetrating Power: High (Lead and Concrete)
enough energy to knock electrons from atoms forming ions, capable of causing cancer (gamma-X-rays-UV)
Atoms of the same element that have different numbers of neutrons and therefore different mass numbers
How Nuclei of Unstable an isotope gain stability
(Spontaneous Decay) : Trying to correct the Neutron to Proton Ratio
Band (Belt) of stability
A Graph that shows the number of neutrons to the number of protons; stable nuclei are found in the shaded area
An atoms which emits an alpha particle (a helium nucleus) is called an alpha emitter
- atomic number of daughter nucleus will be decreased by 2 and the mass number will be decreased by 4
What affects Radioactive Substances
NOTHING: Radioactive substances decay at a constant rate an CANNOT be altered by factors such as temperature, pressure, or chemical combination
What happens during a half life
(16mg --> 8 mg --> 4 mg --> 2 mg) After 3 halve lives the other 14 grams was transformed into other substances
The half-life of 232Th is 1.4 x 10^10 years. If there are 25.0 g of the sample left after 2.8 x 10^10 years, how many grams were in the original sample?
There are 5.0 g of 131I left after 40.35 days. How many grams were in the original sample if its half-life is 8.07 days
Because radioisotopes chemically resemble the stable isotopes of the same element they can be used as tracers to follow the course of a reaction
Radioactive isotopes used for diagnostic purposes
Should have SHORT half-lives and be QUICKLY eliminated from the body
Example of Carbon (14-12) Dating
When a tree takes in CO2, it takes in C-14 and C-12. When the ratio of C-14 to C-12 is the same ratio as in the atmosphere. But when the tree dies the C-14 decays and is not replaced and thereby changing the ratio over time
Radiation allows food to be stored longer by eliminating bacteria, yeast, molds, and insects from food
Induced Artificial Transmutation
Artificial transmutation can be induced by the BOMBARDMENT of the nucleus by high-energy particles
Cyclotron or synchrotron
Use electric and magnetic fields to provide charged particles, such as an alpha particle with sufficient kinetic energy to overcome electrostatic forces and penetrate a target nucleus
Second way of Artificial Transmutation
Occurs when a neutron collides with a target nucleus. The neutrons can be obtained as by-products of nuclear reactors, since the neutron doesn't have a charge, it is not repelled by the target nucleus.
Nuclear Reactions vs. Chemical Reactions
The energy released during nuclear reactions is far greater than the energy given off from chemical reactions
The SPLITTING of a nucleus into smaller fragments, accompanied by the release of neutrons and a large amount of energy
- Results from Neutron Capture
- Result is unstable
Must be PU-239, U-235, or U-233!
- Has one nuclear isotope combine with a neutron to form two real isotopes, a neutron, and energy
- The reaction is controlled and able to produce useful energy
Problems with Fission Reactors
- Radioactive waste
- Storage is difficult to find
- Time Consuming and costly
- Health hazards
Process of combining light nuclei to produce a nucleus of greater mass
- process that the sun uses to produce energy
- HYDROGEN NUCLEI REACT TO PRODUCE HELIUM
Fusion vs. Fission
- Nuclear fusion releases more energy than nuclear fission for a given mass of fuel
- Nuclear fusion power plants would produce little radioactive waste (unlike fission)
- Potential fuels readily available
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