Chapter 4: The Structure of the Atom
Dalton's atomic theory
states that all matter is composed of atoms
calculating % abundance of each isotope
A(x) + B(1-x) = atomic mass
gold foil experiment
Rutherford shot alpha particles at an atom, expecting none of them to be deflected. However, a few rebounded almost directly backwards.
Democritus (billiard ball theory)
atoms are the smallest building blocks in the universe
Rutherford (classical solar system)
atoms have a positively charged nucleus around which electrons orbited
isotopes
atoms with the same number of protons but different numbers of neutrons
Shrödinger model
electrons can be found in various orbitals; model describes the probability of finding an electron in any one orbital
Bohr model
electrons orbit nucleus in clearly defined energy levels
Thomson (plum pudding)
electrons were negatively charged particles scattered throughout a cloud of positive charge
atomic mass unit
equal to 1/12 the mass of a carbon-12 atom
gamma ray
high-energy radiation that has no charge and no mass
de Broglie (wave-particle model)
particles (electrons, protons, etc.) have properties of both waves and particles
radioactive decay
process (not requiring energy) by which unstable nuclei lose energy
radioactivity
process whereby some substances spontaneously emit radiation
alpha radiation
radiation deflected towards the negatively charged plate; has a charge of 2+
beta radiation
radiation deflected towards the positively charged plate
cathode ray
ray of radiation traveling from the cathode to the anode
nuclear reaction
reaction involving change in atom's nucleus
nuclear equation
shows atomic number and mass number
nucleus
the center-most part of an atom where the protons and neutrons are contained
radiation
the rays and particles emitted by radioactive material
atom
the smallest particle of an element that retains the properties of that element
atomic mass
the weighted average mass of an element's isotopes
symbolic notation
upper left - mass number; lower left - atomic number
relationship between % abundance of two isotopes
x + y = 1
