GenChem Flashcards
these are properties that can be observed or measured.
Examples: color, mass, length,
volume, density, state,
conductivity, temperature.
Physical Properties
these are properties that determine whether or not a substance will react chemically.
Chemical Properties
Each element is composed of extremely small particles called atoms. All the atoms of a given element are identical, but they differ from those of any other element. Compounds form by combining atoms
Dalton’s Billiard Ball Model (1803)
The atom is made up of negative electrons that float in a sphere of positive charge like plums in a pudding. He discovered electron (cathode ray experiment) in 1897 and
isotopes in 1913.
Thomson’s Plum Pudding Model (1904)
Discovered the nucleus of a gold atom with his “gold foil”experiment. The atom is
mostly empty space.
Rutherford’s Nuclear Model (1911)
Nucleus surrounded by orbiting electrons at different energy levels. Electrons have definite orbits.
Bohr’s Planetary Model (1913)
“Law of Triad” (1829)
groups of 3’s
- iron, cobalt and nickel
- chlorine, bromine and iodine.
Johann Wolfgang Dobereiner
“Law of
Octaves” (1864)
group of 8s
- lithium to sodium
- fluorine to chlorine
John Newlands
- recognized the repeating pattern or the periodic behavior among elements.
- relationship of the atomic volume & relative atomic mass
Julius Lothar Meyer
formulated the Periodic Law.
Dmitri Mendeleev
is the ability of the atom to donate electrons.
Metallic Property
is the amount of energy required to remove an electron from an atom or ion.
Ionization Energy
is the change in energy when an electron is accepted by a gaseous atom to form an anion.
Electron Affinity
the orbitals of an atom must be filled up in
increasing energy levels.
Aufbau Principle
no two electrons in an atom can have the same set of quantum
numbers and an atomic orbital must contain a maximum of two
electrons with opposite spins.
Pauli’s Exclusion Principle
