Unit Three: Atoms, Moles, and Nuclear Chemistry
nuclear fission
occurs when one atom’s nucleus splits
apart
apart
atom
the smallest component of an element, consisting of a nucleus containing neutrons and protons and one or more electrons
atomic number
the number of protons in the nucleus of a given element
average atomic mass
average mass per atom of an element
electron
particle that is a fundamental constituent of matter, having a negative charge
isotope
two or more forms of an element, having the same number of protons, but having different numbers of neutrons
mass number
the integer nearest in value to the atomic weight of an atom
nucleus
within an atom, containing protons and neutrons
neutron
a neutrally charged particle of matter, found in nucleus
proton
a positively charged particle of matter, found in nucleus
atomic mass unit
a unit of mass used to express atomic and molecular weights
molar mass
the mass in grams of 1 mole of a substance
mole
a unit of counting, one mole = 6.02 x 10^23 particles, atoms, ect.
alpha radiation
-Made of 2 protons and 2 neutrons
-+2 charge
-Helium nucleus
-Stopped by paper
-2nd leading cause of lung cancer
-Used in smoke
-+2 charge
-Helium nucleus
-Stopped by paper
-2nd leading cause of lung cancer
-Used in smoke
beta radiation
-High speed electron
-Charge of -1
-No mass
-Stopped by plastic, thin sheet of metal, or wood
-Used in PET scans
-Charge of -1
-No mass
-Stopped by plastic, thin sheet of metal, or wood
-Used in PET scans
gamma rays
-Most penetrating and dangerous form of
radiation
-Can damage human skin, DNA and
organs
-Some can be stopped by lead or concrete
-Used to kill cancerous cells
-Pure energy
radiation
-Can damage human skin, DNA and
organs
-Some can be stopped by lead or concrete
-Used to kill cancerous cells
-Pure energy
half life
the time required for one-half of a radioisotope’s nuclei to decay into its products
nuclear decay
when an element has an unstable isotope, it becomes radioactive
nuclear fusion
occurs when two or more atoms nuclei come together to form one atom
transmutation
change of an atom of one element to another element through nuclear reactions