Nuclear Chemistry Flashcards
nuclide
atom (in nuclear chemistry) that is identified by the number of protons and neutrons in its nucleus
nucleons
protons and neutrons
nuclear reaction
reaction that affects the nucleus of an atom
transmutation
change in the identity of a nucleus as a result of a change in the number of protons
radioactive decay
nuclear decay
spontaneous disintegration of a nucleus into a slightly lighter nucleus
accompanied by emission of particles, electromagnetic radiation, or both
nuclear radiation
particles or electromagnetic radiation emitted from the nucleus during radioactive decay
types of radioactive decay
alpha emission
beta emission
positron emission
electron capture
gamma emission
alpha particle
two protons and two neutrons bound together
helium nuclei with a charge of 2+
can cause damage in ingested or inhaled
range of alpha particle
a few centimeters in air
penetrating ability of alpha particle
low penetrating ability due to large mass and charge
alpha emission
process in which an alpha particle is emitted from the nucleus of an atom
occurs in very heavy nuclei
causes atomic number to decrease by 2
causes mass number to decrease by 4
beta particle
electron
range of beta particle
a few meters in air
penetrating ability of beta particle
penetrating ability about 100 times greater than that of alpha particles
speed of beta particle
close to the speed of light
beta emission
release of an beta particle (electron) from a nucleus
occurs in atoms nuclei with too many neutrons
causes atomic number to increase by 1
causes mass number to stay unchanged
positron
positively charged particle that has the same mass as an electron
positron emission
release of a positron from a nucleus
occurs in nuclei with too many protons
causes atomic number to decrease by 1
causes mass number to stay unchanged
electron capture
process in which an inner orbital electron is captured by the nucleus of the atom that contains the electron
occurs in nuclei with too many protons
causes atomic number to decrease by 1
causes mass number to stay unchanged
gamma rays
high-energy electromagnetic waves emitted from a nucleus as it changes from an excited energy state to a ground energy state
penetrating ability of gamma particle
greatest of all particles
gamma emission
emission of gamma rays from a nucleus
usually occurs immediately following other types of decay (when nucleus is left in an excited state)
half-life
time required for half the atoms of a radioactive nuclide to decay
roentgen
a unit used to measure nuclear radiation
equal to the amount of radiation that produces 2 × 109 ion pairs when passing through 1cm³ of dry air
rem
the quantity of ionizing radiation that does as much damage to human tissue as done by 1 roentgen of high-voltage X-rays
nuclear fission
a nuclear reaction in which a heavy nucleus splits into more-stable nuclei of intermediate mass
releases enormous amounts of energy
can occur spontaneously or upon impact with another particle
nuclear fusion
a nuclear reaction in which light-mass nuclei combine to form a heavier, more stable nucleus
releases even more energy per gram of fuel than nuclear fission
mass defect
difference between the mass of an atom and the sum of the masses of its protons, neutrons, and electrons
nuclear binding energy
energy released when a nucleus is formed from nucleons
nuclear shell model
states that nucleons exist in different energy levels (or shells) in the nucleus
radioactive nuclide
unstable nucleus that undergoes radioactive decay
transuranium elements
elements with more than 92 protons in their nuclei
produced by artificial transmutations
