The Atom Flashcards
Law of constant composition
a compound always contains atoms of two or more elements combined in definitw porportions of mass and composition
Law of multiple prportions
atoms with 2 or more elements that may combine in differnt ratios
ex: NO, NO2, N2O
Daltons atomic theory
- indivisible and indestructible particles
- atoms of same elements have same masses
- atoms of different elements have different masses
- atoms combine in whole number ratios
Objections to Daltons theory
- atoms are not indivisible– subatomic particles
- not all atoms of same elements have same masses– isoptopes
JJ Thompson
- Cathode Ray:electron
- plum pudding : electrons are scattered unevenly and surrounded by positive charge to balance negative
- established presence of proton
Oil Drop Experiment
- Milikan
- by varying charges on plates, found that he could suspend the drops of oil
Proton
- e goldstein
Ernest Rutherford
- Gold foil
- concluded that atoms have empty space and a nucleus
Subatomic Particles
- neutrons
Niels Bohr
- bohr model
- electrons move in definite orbitals around the nucleus
Particle Wave Dulaity
-Einstein
-
Uncertainity Pribicple
- Heisenbrg
- impossible to know the location and momentum of an electron and the best that can be done is finding the probability
Edwin Schoedinger
- propsed electrons are waves
Aufbau Principle
lowest energy possible
Pauli exclusion principle
want space to minimize repulsion (2 electrons per orbital)
Hunds rule of Maximum multiplicity
filll up the spaces only if they have to
