Chem Quiz Flashcards
Democritus
atoms are “uncuttable”, and have different shapes
John Dalton
atoms are tiny balls that arrange in different ways to make different compounds
JJ Thomson
atoms are positive spheres with negative electrons in them
*discovery of electron
Ernest Rutheford
atoms are mostly empty space
*discovery of nucleus
Niels Bohr
electrons travel in an orbit around the nucleus, specific number in each orbit
Qantum mechanical model
by, Einstein, De Broglie, Heisenberg, Schrodinger, Chadwick
Pauli exclusion principle
each orbit can hold 2 electrons with opposite spins
Aufbau principle
electrons fill the lowest energy orbitals first
Hund’s rule
place one negative electron per orbital before doubling up
(empty bus seat rule)
Atomic radius
increases left down
ionization energy
increases up right
Louis de Brogile
applied wave particle theory to -e
Heisenberg uncertainty rule
impossible to know the velocity and position of an electron at the same time
Schrodinger wave equation
limited number of solutions
quantized energy levels, probability of finding a -e
Orbital (electron cloud)
region in space where there is 90% probability of finding a -e
