Unit 1 Flashcards
(13 cards)
Name the new model devised by: Dalton
Billiard ball model, each atom is indivisible
Name the experiment done by and the new model devised by: Thomson
Cathode ray tube experiment, discovered identical negatively charged electrons in all matter and created “plum pudding” model with electrons embedded in a positive sphere
Name the experiment done by and the new model devised by: Rutherford
Gold foil experiments; shooting alpha particles at gold foil revealed each atom was mostly empty space, led to the planetary model with electrons orbiting a tiny nucleus
Name the experiment done by and the new model devised by: Bohr
Using tthe photoelectric effect of different elements (electrons launched off under different circumstances), he determined there were specific energy levels in atoms
Name the new model devised by: Schrodinger
Wave function electron cloud model and quantum motion
What does the Aufbau principle state?
Electrons are added in order of increasing energy; the following energy level is not added to until the current one is totally full
Pauli Exclusion Principle
Each orbital can hold 0, 1, or 2 electrons, and if there’s two, they must have opposite spins
Hund’s Rule
Electrons in the same sub-level (e.g. 2p) will be added first with one spin direction in each orbital, and then they will be filled with electrons of the opposite spin.
What elements can be involved in hydrogen bonding?
N, O, and F
What is polarizability?
The ability of a molecule to gain a random temporary charge induced by London Dispersion Forces
What difference in electronegativity is considered polar?
0.5
Factors affecting state of matter in compounds
Polarity (dipole moment), lattice energy, hydrogen bonding, London dispersion forces
What makes a compound electrically conductive?
Free-to-move electronically charged species. Molecular compounds never have these, and solid ionic compounds have them locked into a grid. In ionic solutions, they CAN conduct electricity.
