New Text Document
Home > Flashcards > Print Preview
The flashcards below were created by user
on FreezingBlue Flashcards
. What would you like to do?
bombarded light nuclei with alpha particles and caused them to eject neutrons.
Antoine Henri Becquerel
triads as they became known were groups of three elements having very similar properties in which the atomic mass of the central element is nearly the average (arithmetic mean) of that for the other two elements.
arranged the elements by atomic mass along a spiral wrapped around a metal cylinder which he called the telluric helix because tellurium was the element in the middle of the plot. When the elements were so arranged, elements with similar properties were found to lie in columns running parallel to the axis of the cylinder.
oil drop experiment: Millikan was able to determine the charges on the droplets
CANAL RAYS: discover proton
- Gold foil is bombarded by energetic alpha particles (with a positive charge) coming from a radioactive source. => no plum pudding, NUCLEUS.
- NUCLEAR MODEL OF THE ATOM: An atom is largely empty space and consists of a small, massive positively-charged nucleus surrounded by small electrons (akin to a microscopic solar system)
- Predict existence of neutrons
- CHEMICAL ATOMIC THEORY
- Law of Multiple Proportions: If two elements form more than one compound between them, then the ratio of the masses of the second element which combine with a fixed mass of the first element will be small whole number (rational) ratios.
observed that the fluorescent spot could be moved by a magnet and determined that the rays moved from the cathode (-) to the anode (+) and coined the term cathode rays
George Johnstone Stoney
he proposed that these cathode rays were in fact negatively charged particles that he named ELECTRONS
- Thomson performed an ingenious experiment of balancing (or cancelling) deflection of the rays by an electric field with an equal but opposite deflection due to a magnetic field. Then using the laws of physics he determined the charge:mass ratio (e/m) for these electrons
- plum pudding model of the atom
PAULI EXCLUSION PRINCIPLE: No two electrons in the same atom can have EXACTLY the same set of four quantum numbers,
HUNDS RULE OF MAXIMUM MULTIPLICITY (spin): Electrons remain unpaired as much as possible (within a set of orbitals with equal energies (these orbitals are said to be DEGENERATE) must be satisfied.
Sir Karl Popper
hypothetico-deductive method: based on FALSIFIABILITY, the potential to show that something is false by observation or experiment.
(the inductive method). A SCIENTIFIC LAW is a concise and generally applicable statement of a scientific principle
Louis de Broglie
postulated that particles could act in a wave-like manner.
Davisson and Germer
scattered electrons off of a nickel crystal, and observed in the scattered intensity profile, diffraction patterns (regularly alternating light and dark spots) --- a WAVE phenomenon.
classified the elements (by arranging them in order of increasing atomic mass) into groups with analogous properties. Law of Octaves.
Julius Lothar Meyer
Periodic table (not good one =))
the atoms (oscillators) in the heated body cannot emit energy in any arbitrary amount (as they could according to classical physics). Instead the radiant energy could only be emitted in discrete bundles called QUANTA with energy ,
used Plancks quantum formula. => find out why v0
Johann Jakob Balmer
First fomular for hydrogen emission spectrum
General hydrogen emission spectrum
Bohr was able to theoretically derive the EMPIRICAL Rydberg constant.
What would you like to do?
Home > Flashcards > Print Preview