Chemistry Chapter 21 Nuclear Chemistry Test Review

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protons and neutrons
An atom identified by the number of protons and neutrons in its nucleus
mass defect
The difference between the mass of an atom and the sum of the masses of its protons, neutrons, and electrons
nuclear binding energy
The energy released when a nucleus is formed from nucleons; a measure of the stability of a nucleus
binding energy per nucleon
Binding energy per nucleus divided by the number of nucleons it contains
band of stability
The stable nuclei cluster over a range of neutron:proton ratios (the most stable having a ration of approx. 1:1)
nuclear shell model
A model that nucleons exist in different energy levels (shells) in the nucleus
magic numbers
The numbers of nucleons that represent completed nuclear energy levels (2, 8, 20, 28, 50, 82, 126)
nuclear reaction
A reaction that affects the nucleus of an atom
A change in the identity of a nucleus as a result of a change in the number of its protons
radioactive decay
The spontaneous disintegration of a nucleus into a slightly lighter nucleus, accompanied by emission of radiation, the number capture or ejection of electrons, or fission
nuclear radiation
Particles or electromagnetic radiation that are released from the nucleus during radioactive decay, such as neutrons, electrons, and photons
radioactive nuclide
An unstable nucleus that undergoes radioactive decay
A nuclide that contains isotopes that decay and that emit radiation
Two protons and two neutrons bound together and is emitted from the nucleus during some kinds of radioactive decay (restricted almost entirely to very heavy nuclei). Sheet of paper/clothing can stop this kind of radation (least penetrating).
4/2 He
Alpha emission
An electron emitted from the nucleus during some kinds of radioactive decay; neutrons can be converted to protons AND electrons; atomic number increases by one and mass number stays the same. Type of radation that can be stopped by a piece of wood
1/0 n –> 1/1 p + 0/-1 B –> 0/-1 e (0/-1 B)
beta emission
A particle that has the same mass as an electron, but has a positive charge and is emitted from the nucleus during some kinds of radioactive decay; protons can be converted into neutrons; atomic number decreases by one and mass number stays the same
1/1 p –> 1/0 n + 0/1 B –> 0/1 e (0/1 B)
positron emission
electron capture
An inner orbital electron is captured by the nucleus of its own atom; inner orbital electrons converted to neutrons; atomic number decreases by one and mass number stays the same
1/1 p + 0/-1 e –> 1/0 n
electron capture
High-energy electromagnetic waves emitted from a nucleus as it changes from an excited state to a ground energy state; shorter rays than light; very dangerous in large quantities. Type of radiation that can be stopped by several inches of lead
The time required for half the atoms of a radioactive nuclide to decay
given: two amounts of time
1. time elapsed / time of half life (to find number of half-lives)
2. divide sample by 2^n, where n = number of half-lives
given: two masses
1. starting amount / 2^n (to find number of half-lives that have occurred)
2. a. how long does it take? half lives x time given
b. what is the life life? time given / number of half lives
decay series
A series of radioactive nuclides produced by successive radioactive decay until a stable nuclide is reached
parent nuclide
A radionuclide that yields a specific daughter nuclide as a later member of a radioactive series. The heaviest nuclide of each decay series
daughter nuclides
The nuclides produced by the decay of another nuclides
artificial radioactive nuclides
Radioactive nuclides not found naturally on Earth; made by artificial transmutations
artificial transmutations
The transformation of atoms of one element into atoms of another element as a result of a nuclear reaction, such as bombardment with neutrons.
The bombardment of nuclei with charged and uncharged particles
transuranium elements
Elements with more than 92 protons in their nuclei; produced by artificial transmutations
roentgen (R)
A unit used to measure nuclear radiation exposure; equals the amount of gamma and x-ray radiation that produces 2.58 x 10^-4 ion pairs when it passes through 1 cubic cm of dry air
A unit measuring the dose of any type of ionizing radiation that factors in the effect that the radiation has on human tissue
film badges
Use exposure of film to measure the approximate radiation exposure of people working with radiation
Geiger-Muller counters
Instruments that detect radiation by counting electric pulses carried by gas ionized by radiation
scintillation counters
Instruments that convert scintillating light to an electric signal for detecting and measuring radiation
radioactive dating
The process by which the approximate age of an object is determined based on the amount of certain radioactive nuclides present (uses Carbon-14 to estimate the age of organic materials up to about 50,000 years old)
radioactive tracers
A radioactive material that is added to a substance so that its distribution can be detected later
nuclear waste
Product of both fission and fusion; dangerous to living organisms and needs to be contained, either via on-site storage or off-site disposal. Waste that contains radioisotopes.
nuclear fission
A very heavy nucleus splits into more stable nuclei of intermediate masses; can occur spontaneously or when nuclei are bombarded by particles; enormous amounts of energy released
chain reaction
A reaction in which the material that starts the reaction is also one of the products and can start another reaction
critical mass
The minimum amount of nuclide that provides the number of neutrons needed to sustain a chain reaction
nuclear reactors
A device that uses controlled-fission chain reactions to produce energy and radioactive nuclides
nuclear power plants
A facility that uses heat from nuclear reactors to produce electrical energy. Uses energy as heat from nuclear reactors to produce electrical energy; five main components: shielding, fuel, control rods, moderator, and coolant.
A radiation-absorbing material used to decrease exposure to radiation (esp. gamma rays) from nuclear reactors
fissile fuel
usually Uranium-235
Absorbs the energy as heat that is produced in a nuclear power plant
control rods
Neutron-absorbing rods that help control the reaction by limiting the number of free neutrons
Used to slow down the fast neutrons produced in a nuclear power plant
nuclear fusion
Low-mass nuclei combine to form a heavier, more stable nucleus; releases even more energy per gram of fuel than fission; can be used for energy generation
alpha, beta, and gamma
Three main types pf radiation
alpha symbol
alpha symbol
beta symbol
beta symbol
gamma symbol
gamma symbol
Unstable nucleus emits ________ when it decays
alpha particle
Ionizing radiation that consists of a helium nuclei is an ____________
nuclear symbol
nuclear symbol
hyphen notation
hyphen notation
Geiger-Muller Counters
Film Badges
Scintillation Counters
Detecting radiation (3 ways)
Mass can be converted to energy, and energy to mass
Energy=Mass x Speed of Light^2
Albert Einstein’s equation
gamma rays
High energy rays
ionizing radiation
Not neutral and takes electrons away
positron symbol
positron symbol
neutron symbol
neutron symbol
proton symbol
proton symbol
Radioactive decay or bombarding the atom
2 ways to change the identity of a nucleus
left side
right side
right side
left side
strong nuclear force
The strongest of the four fundamental forces in nature. It holds the nucleus together. The attraction of the strong nuclear force is what keeps the nucleus from flying apart.
None of them. Although the slang term for a highly radioactive area or sample is “hot,” radioactivity cannot be felt, seen, or otherwise sensed without the use of radiation-detecting instruments.
Which of the five senses can detect radioactivity?
It’s impossible to change the rate of nuclear decay in a radioactive isotope. The rate of radioactive decay is not changed by any factors that usually affect chemical reactions, such as adding or removing heat, raising or lowering pressure, etc.
Name one thing you can do change the rate of nuclear decay in a radioactive isotope.
The atomic number goes up by one, which by definition means that it gains a proton and becomes a different element with a different atomic number.
What happens to the atomic number of an element when it undergoes beta decay?
Nothing. The mass number is the number of protons and neutrons.
What happens to the mass number of an element when it undergoes beta decay?
They are radioactive elements with atomic numbers greater than 92.
When is one a radioactive element?
Fusion must take place at extremely high temperatures
Why is nuclear fusion considered an impractical source of energy today?
nuclear fission reaction
When uranium-235 splits
Two nuclei of low mass would most likely undergo nuclear fusion
Which uranium is most commonly used?
250 radioactive
1100 isotopes
Thigh- Iodine
Treat Cancer-Cobalt-60
Nuclear Waste
What is the one thing most people fear about?
amount of radiation exposed to
amount of radiation absorbed to
relative biological effectiveness
Madam Curiy
Who discovered radiation?
Madam Curiy
Who discovered radium?
Categories: Nuclear Chemistry