Chapter 19 and 20 Flashcards
Any element that emits radiation.
Radioactive
- are a combination of 2 protons and 2 neutrons.
•generally don’t penetrate solid materials. Can cause damage to the surface of living tissue.
Alpha particles
What are the three types of radioactivity?
Alpha particle , beta particle, gamma radiation
Electron ejected from the nucleus of an atom.
•can penetrate light materials like paper or clothing but not denser materials like aluminum.
Beta particle
Pure energy. It carries no electric charge and has no mass.
Gamma radiation
Can penetrate most materials.
Generally the most harmful type of radiation.
Can be absorbed by lead.
Gamma radiation
The process by which certain elements emit radiation.
Radioactivity
What does excess exposure to radiation cause?
Mutations in a cell’s DNA and can cause cancer.
The force of interaction between all nucleons. Effective only at close distances.
Strong nuclear force
The changing of one element into another.
Transmutation
Element loses an alpha particle the atomic number decreases by 2 and mass number drop by four.
Element loses a beta particle the atomic number increases by one and mass number stays constant.
Radioactive decay
The time required for half the atoms in a sample of a radioactive isotope to decay.
The shorter the half life the faster the radioactive isotope decays.
Half life
A means of measuring the remaining radioactive carbon fourteen and telling how old a substance is.
Carbon 14 half life- 5730 years
Accurate to 75,000 years
Carbon 14 dating
The splitting of an atomic nucleus into fragments.
Nuclear fission
A self sustaining reaction in which the products of one reaction cause more reactions in the substance.
Chain reaction
The minimum mass of fissionable material in a nuclear reactor (or bomb) that will sustain a chain reaction.
Critical mass
Contain 3 components: nuclear fuel, control rods, and liquid.
Nuclear fission reactors
U-238 and 3% U- 235 (fuel rods)
Nuclear fuel
Determine the number of neutrons available for the reaction to occur.
Control rods
What is pressurized and heated by the fuel? It is transferred to heat and a second water system that generates steam that generates steam and turns a turbine to generate electricity. The two systems never mix.
Water- (this process converts nuclear energy to electrical energy)
Special nuclear reactor that allows the transmutation of U-238 into a variety of over elements thereby generating more electricity.
Breeder reactor
What happens as atoms split (U)?
The overall mass of the two fragments decreases. The mass that is lost is converted to energy.
The combing of small nuclei into larger atoms and generating energy.
Nuclear fusion
Fusion that occurs at very high temps. Sun.
Thermonuclear fusion
