CHEM 24
The extremely small, positively charged dense center of an atom
-nucleus
Found that invisible rays were emitted when electrons bombarded the surface of certain materials
-Wilhelm Roentgen
High energy emissions that caused photographic plates to darken
-x-rays
Was studying minerals that emit light after being exposed to sunlight
-Henri Becquerel
Minerals that emit light after being exposed to sunlight
-phosphorescence
Occur when bonds are broken and formed
-chemical reactions
Occur when nuclei combine split, and emit radiation
-nuclear reactions
Named the process by which materials give off such rays
-Marie Curie
The process Marie Curie named
-radioactivity
The rays and particles emitted by a radioactive source
-radiation
Isotopes of atoms with unstable nuclei
-radioisotopes
Performed the famous gold foil experiment that helped define modern atomic structure
-Ernest Rutherford
Identified alpha, beta, and gamma radiation
-Ernest Rutherford
Has the same composition as a helium nucleus (two protons and two neutrons)
-alpha particle
A very fast-moving electron that is emitted when a neutron in an unstable nucleus converts into a proton
-beta particle
Are photons, which are high-energy (short wavelength) electromagnetic radiation
-gamma rays
Are a form of high-energy electromagnetic radiation that are not produced by radioactive sources
-x-rays
The ability of radiation to pass through matter
-penetrating power
The conversion of an element into another element by radioactive decay
-transmutation
Protons and neutrons
-nucleons
Acts on subatomic particles that are extremely close together and overcomes the electrostatic repulsion among protons
-strong nuclear force
Acts between two charged particles
-electrostatic force
The area on the graph within which all stable nuclei are found
-band of stability
A radiostope that lies above the band of stability is unstable because it has too many neutrons relative to its number of protons
-beta decay
Spontaneously radioactive
-unstable
All nuclei with more than 82 protons are radioactive and decay spontaneously
-alpha decay
A radioactive decay process that involves the emission of a positron from a nucleus
-positron emission
A particle with the same mass as an electron but opposite charge
-positron
Occurs when the nucleus of an atom draws in a surrounding electron, usually one from the lowest energy level
-electron capture
A series of nuclear reactions that begins with an unstable nucleus and results in the formation of a stable nucleus
-radioactive decay series
The time required for one-half of a radioisotope’s nuclei to decay into its products
-half-life
The process of determining the age of an object by measuring the amount of a certain radioisotope remaining in that object
-radiochemical dating
Used to measure the age of artifacts that were once part of a living organism
-carbon dating
Has a half-file of 5730 years
-carbon-14
The process that involves striking nuclei with high-velocity particles
-induced transmutation
The elements following uranium in the periodic table (element 93+)
-transuranium elements
States that any reaction produces or consumes energy due to a loss of gain in mass
-Einstein’s equation
The difference in mass between a nucleus and its component nucleons
-mass defect
The splitting of a nucleus into fragments
-nuclear fission
A sample that is massive enough to sustain a chain reaction has
-critical mass
Reactors able to produce more fuel than they use
-breeder reactors
The combining of atomic nuclei
-nuclear fusion
Fusion reactions are also known as
-thermonuclear reactions
The bombardment of nuclei with particles in order to create new elements
-induced transmutation
Radiation energetic enough to ionize matter which it collides with
-ionizing radiation
Used to detect and measure radiation levels
-geiger counter
A radioscope that emits non-ionizing radiation and is used to signal the presence of an element or specific substance
-radiotracer
Another radiation-based medical diagnostic tool
-positron emission transaxial tomography (PET)
Refers to the amount of radiation a body absorbs from a radioactive source
-dose of radiation