Chemistry unit 4–nuclear chemistry exam review

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nuclear reactions
1. elements may be converted from one to another
2. particles within the nucleus are involved
3. tremendous amounts of energy are released or absorbed (potential energy)
4. rate of reaction is not influenced by external factors
ordinary chemical reactions
1. no new elements can be produced
2. only the electrons participate
3. relatively small amounts of energy
4. rate of reaction depends on factors such as concentration, temperature, catalyst and pressure
the spontaneously decomposition of a nucleus to form a different nucleus
nuclear radiation
involve a change in the nucleus of an atom
different atomic forms of all elements
any particle found in the nucleus of an atom (proton&neutron)
radioactive isotope (radionuclide)
has an unstable nucleus and spontaneously emits a particle and decays into another element
any substance that emit particles or energy, especially high-energy particles that cause ionization.
alpha particle
helium nucleus; 2+ charge; low penetration; burn skin severely (symbol)
beta particle
electron; 1-charge; low to moderate, depending on energy; burn skin severely (symbol)
proton, H nucleus; 1+ charge; low to moderate, depending on energy (symbol)
gamma radiation
high-energy electromagnetic radiations such as X-rays; 0; high; burn skin and internal organs even damage DNA (symbol)
neutron; 0; very high; burn skin and internal organs even damage DNA (symbol)
band of stability
1-20: n/p=1:1
20-83: n/p=1.5:1
83-: not stable
mass defect (mass deficiency)
the difference between masses of atoms and the sum of their constituent particles (masses are always less than the sum)
nuclear binding energy
the energy which is converted from the mass deficiency and released.
the time it takes for half of the mass of a radioactive sample to decay, ranges from a fraction of a second to billions of years, and is not affected by external conditions
nuclear reactions in which result a given nuclide undergoes a change in the number of protons, resulting in the formation of a different element
artificial transmutation
occur in cyclotrons or linear accelerators, carried out by bombarding one nuclide with other nuclides such as neutrons, protons or alpha particles.
a reaction where one large nuclide splits into two or more nuclei of intermediate masses, usually accompanied by the emission of one or more neutrons
a reaction occurs when two or more light-weight nuclei join together to form a heavier nucleus. Produce much more energy than fission
chain reaction
a reaction start with a neutron bombardment and end with the release of neutron, releasing enormous amounts of energy
nuclear reactor
a reactor control the chain reaction and the resulting energy is harnessed to perform work or produce electricity
fuel rods
contain the fissionable uranium
contains heavy water(D2O)-slow the high-energy neutron. Used to control fission reaction
control rods
made up of graphite to absorb high-energy neutrons and control the speed of a nuclear reaction
a reinforce concrete that cover the radioactive substances and prevent them from harming people by radiation
critical mass
the minimum amount of radioactive material which can sustain a chain reaction
decay series
a series of decay in which radioactive element is decomposed in different elements until it produces one stable atom.
parent nuclide
the decaying nuclide in one nuclear reaction
daughter nuclide
the product nuclide in one nuclear reaction
particle accelerator
the excessive heat energy make the equipment meltdown and make nuclear waste leak
a disaster occurred in Russia which the explosion of nuclear reactor results in huge loss of economy and lives
Yucca mountain
a project which make all the nuclear pollutant deep enough to prevent terrorists
thermal pollution
a pollution by pouring hot water and the dissolving gases escape, making fish cannot breathe
beta emission
1 1 0
n→ p + β
0 1 -1
positron emission
1 1 0
p→ n + β
1 0 +1
electron capture
106 0 106
Ag + e → Pd
47 -1 46
alpha emission
226 222 4
Ra → Rn + He
88 86 2
Categories: Nuclear Chemistry