Introduction to Nuclear Chemistry Quiz- Chem
Isotopes
atoms of the same element that have the same atomic number but different atomic masses due to a different number of neutrons
Atomic Number
the number of protons in the nucleus of an atom of an element
Radiation
the penetrating rays and particles emitted by a radioactive source
Radioactivity
the process by which nuclei emit particles and rays
Transmutation
the conversion of an atom of one element to an atom of another element
The experiments of Antoine Henri Becquerel that led to the discovery of radioactivity
observed that pitchblende (a mineral containing uranium) produced an energy that could fog photographic plates when exposed to sunlight and observed that when he sat the uranium in a closed draw with the photographic plate, it still left an image on the film; concluded that there is spontaneous emission of energy from uranium
The property that determines whether an isotope/radioisotope is stable or unstable (radioactive)
# of neutrons; ratio of protons : neutrons
Law #1 relating property of radioactivity
Elements with an atomic number between 1-20 are stable if the proton ratio is equal to 1:1
Law #2 relating property of radioactivity
Elements with an atomic number between 21-83 are stable if the proton ratio is between 1:1 and 1:1.5
Law #3 relating property of radioactivity
Elements with atomic numbers beyond 83 have no stable isotopes
Contributions of Marie and Pierre Curie in the field of nuclear chemistry
defined “radioactivity” and “radiation”; discovered 2 radioactive materials: polonium and radium; discovered radiation sickness or the hazard of radiation to life
Contributions of Ernest Rutherford in the field of nuclear chemistry
discovered 3 types of radiation: alpha, beta, and gamma
Rutherford’s experiment that led him to conclude that there are 3 types of radiation
he directed rays of various radioactive sources through electrical fields; some curved toward the positive end, some toward the negative, and some were unaffected by the field
Alpha radiation
in heavy elements (atomic # > 83) where there are too many protons and neutrons; blocked by a sheet of paper
Beta radiation
occurs in neutron rich radioisotopes; blocked by a sheet of aluminum
Gamma radiation
occurs when unstable atoms emit waves of high energy radiation called gamma rays; blocked by thick concrete
Positron radiation
occurs in neutron rich radioisotopes; blocked by a sheet of aluminum; first anti-matter particle ever detected
Steps for balancing a nuclear equation
#1: determine which element is parent nuclei and daughter nuclei
#2: express each element in proper nomenclature
#3: begin assembling the nuclear equation
#4: balance the atomic mass and atomic number on both sides
#5: identify the missing particle
#6: identify mode of radioactive decay
#2: express each element in proper nomenclature
#3: begin assembling the nuclear equation
#4: balance the atomic mass and atomic number on both sides
#5: identify the missing particle
#6: identify mode of radioactive decay
alpha decay
beta decay
gamma decay
positron decay