Nuclear Chemistry Vocab List – Flashcards
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Alpha Particle
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A positively-charged particle that consists of two protons and two neutrons and that is emitted from a nucleus during radioactive decay. Alpha radiation is the most ionizing and least penetrating of the common nuclear reactions.
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Atom
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The smallest unit of an element that maintains the chemical properties of that element. An atom is electrically neutral.
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Atomic Bomb
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A nuclear weapon in which the energy is released by nuclear fission. An atomic bomb releases less energy than a hydrogen bomb
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Atomic Number
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The number of protons in the nucleus of an atom. The atomic number identifies the element
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Background Radiation
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The nuclear radiation that arises naturally from cosmic rays and from radioactive isotopes in the soil and air. Most of the natural radiation in your body is from 14 C and 40 K
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Beta Particle
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An electron that is emitted from the nucleus during radioactive decay. Beta radiation is moderately ionizing and moderately penetrating
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Chemical Bond
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The attractive force that holds one atom to another atom or one ion to another ion. Changes in chemical bonds releases or absorbs much less energy than the changes in nuclear energy involved in fission or fusion.
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Control Rods
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A cylindrical bar of neutron-absorbing substance used to vary the output of power of a nuclear reactor. Control rods are automatically inserted into the reactor o stop the fission chain reaction when an emergency situation develops.
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Critical Mass
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The minimum amount of fissionable material that can be brought together to produce a nuclear explosion. In an atomic warhead two subcritical masses are stowed separately and are brought together to produce a critical mass.
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Depleted Uranium
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A uranium sample which has almost all of its fissionable isotope (235 U) removed. Depleted Uranium is used to make armor for military vehicles such as tanks and for making the tips of armor piercing artillery shells because uranium is one of the hardest metal known.
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Deuterium
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An isotope of hydrogen that has one neutron
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Dosimeter
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a device used to measure the dose of ionizing radiation a person receives.
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Electromagnetic Wave
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A wave that consists of oscillating electric and magnetic field, which radiate outward at the speed of light. Gamma radiation travels as electromagnetic waves.
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Electron
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A subatomic particle that has a negative charge and is found outside the nucleus. Electrons have a mass that is insignificant compared to the mass of a proton or neutron
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Element
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A substance that cannot be separated or broken down into simpler substances by chemical means. all atoms of an element have the same atomic number which also mean that they have the same number of protons.
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Enrichment
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The process of increasing the amount of the fissionable isotope of uranium 235 U versus the nonfissionable isotope of uranium 238 U. Two methods of uranium enrichment are gaseous diffusion and ultracentrifuge methods.
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(Nuclear) Fission
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The process by which a large nucleus splits into two medium-sized nuclei with the release of extra neutrons and a large amount of energy. Nuclear fission releases less energy than nuclear fusion
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Fossil Fuels
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A nonrenewable energy source in which the remains of organisms that lived long ago rapidly combined with oxygen. The three major fossil fuels are coal, petroleum, and natural gas.
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Fuel Rods
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A bundled assembly of fissionable uranium or plutonium isotopes which under go fission in a nuclear power plant. When fuel rods lose access to a coolant for a significant period of time they could overheat and lead to a meltdown.
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(Nuclear) Fusion
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The process by which tow smaller nuclei are joined to form a larger nucleus with the release of large amounts of energy. Nuclear fusion releases more energy than nuclear fission.
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Gamma Ray
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The form of electromagnetic energy emitted by a nucleus during nuclear fission or during radioactive decay. Gamma radiation is described as being the most penetrating common form of radiation, but is considered to be the least ionizing
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Half-Life
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The time required for half of a sample of a radioactive isotope to break down by radioactive decay to form a daughter isotope. Radioactive isotopes with long half-lives do not give off much ionizing radiation during a reasonable short period of time
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Heat
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The energy transferred between objects that are at different temperatures. Thermal energy is always transferred form the object with higher temperature to the object with lower temperature.
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Hydrogen Bomb
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A nuclear explosive that derives its explosive energy from nuclear fusion. A hydrogen bomb is more powerful than an atomic bomb.
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Ion
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A charged particle formed when a neutral atom or a neutral molecule gains or loses one or more electrons. For an ion the number of protons cannot equal the number of electrons.
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Ionizing Radiation
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radiation that carries enough energy in its high speed particle or photon that it can strip away electrons from a neutral atom or neutral molecule and create charge particles in a living organism. Ionizing radiation can kill living cells or cause mutations in living cells.
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Isotopes
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nuclei which have the same number of protons, but a different number of neutrons. Isotopes of the same element have the same chemical properties and cannot be separated by chemical reaction methods.
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Gaseous Diffusion Method
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A way of enriching uranium that involves passing uranium hexafluoride gas through thousands of ceramic barriers which contain microscopic holes.
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Generator
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A machine that converts mechanical energy into electrical energy. A generator is often connected to a turbine which converts the kinetic energy of a moving fluid into the mechanical energy of a rotating shaft.
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Kinetic Energy
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The energy of an object that is due to the object's motion. The absolute temperature of a substance if directly related to the average kinetic energy of the particles which make up that substance.
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Mass Number
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the number of protons+neutrons in the nucleus of an atom or ion. The mass number of the most common isotope of an element almost always agrees with the atomic mass for the element rounded to the nearest whole number.
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Mass Defect
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The mass lost when a nucleus is made from individual protons and neutrons.
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Metal
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An element that is shiny and has good thermal conductivity and electrical conductivity. With the exception of the element hydrogen, the left side (approx 2/3) of the periodic table contains metallic elements.
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Molecule
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The smallest unit of a substance that is held together by covalent bonding and has no charge. Covalent bonding occurs when two atoms share one or more pairs of electrons to obtain a filled outer shell of electrons
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Mutation
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Changes in a living cell that do not kill the cell, but result in changes in the cell's DNA. Most mutations in cells are negative for the long-term survival of the organism
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Neutron
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A subatomic particle that has no charge and is located in the nucleus of an atom. The mass of a neutron is about the same as the mass of a proton.
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Noble Gas
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One of the elements of group 18 of the periodic table. They are unreactive because they already have a filled outer shell of electrons.
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Nonmental
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An element that has poor thermal conductivity and poor electrical conductivity. The nonmetals are found on the upper right corner of the periodic table.
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Nuclear Chain Reaction
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A continuous series of nuclear fission reactions. A nuclear chain reaction is triggered when a moderate speed neutron is given to an suitable isotope of uranium, plutonium, or thorium.
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Nucleus
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An atom's central region which is extremely tiny and extremely dense. Protons and neutron's are found in the nucleus of an atom.
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Orbital
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a region in an atom where there is a high probability of finding electrons. Chemical energy which comes from changes in the orbitals is much less concentrated than nuclear energy which comes from changes that result from splitting large nuclei or joining small nuclei
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Polyatomic Ion
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A charged particle made up of two or more atoms. Most polyatomic ions are much larger than most monatomic ions.
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Potential Energy
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The energy that an object has because of its position. High potential energy is associated with low stability.
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Power-Grade Uranium
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Uranium which has been enriched to a level of about 3.5% fissionable 235 U so that it can sustain a reaction for thermal purposes, but cannot sustain a nuclear explosion. The Iranian Gov. claims that it is only attempting to create power grade uranium with its centrifuge technology
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Proton
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The subatomic particle that has a positive charge and is located in the nucleus of an atom. The number of protons in the nucleus identifies the element.
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Radiation
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Energy that is transferred by electromagnetic waves or by high speed particles or photons leaving the nucleus of an atom. Nuclear radiation is considered to be ionizing radiation.
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Radioactive Decay
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The disintegration of an unstable nucleus into a different nucleus accompanied by the emission of radiation or the capture of an electron by the nucleus. Each isotope that undergoes nuclear decay has a unique half-life
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Radioactive Trace
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A radioactive material that is added to a substance so that its distribution can be detected later. A radioactive tracer has the same cehmical properties as the nonradioactive element or compound it is imitating.
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Radon
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A noble pas produced by the uranium decay series that presents a health hazard because it emits alpha particles and can enter homes through cracks in the basement floor or cracks in the foundation
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Spent Nuclear Fuel
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Uranium that has all of the readily fissionable 235 U removed during the enrichment process leaving only 238 U
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Temperature
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A measure of the average kinetic energy of a substance. Thermal energy is always transferred from the object with higher temperatures to the object with lower temperatures.
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Tritium
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An isotope of hydrogen with two neutrons
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Ultracentrifuge Method
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A way of enriching uranium which involves spinning a container of uranium hexafluoride in a high speed spinning device
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Uranium Enrichment
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The process of increasing the percentage of readily fissionable 235 U relative to the nonreadily fissionable 238 U.
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Weapons-Grade Uranium
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Material that has been enriched to approximately 90% fissionable 235 U so that it can produce an explosive nuclear reaction if a critical mass is brought together in one place. The major world powers have economic sanctions on Iran because the want to prevent Iran from using their centrifuge technologies to produce weapons-grade uranium.
