Models of Atom Flashcards
Discovery of electron
Plum Pudding Model
Who discovered electron?
JJ Thompson
Negatively charged electrons are dispersed in a positively charged sphere
Plum Pudding Model
Discovery of nucleus and proton
Nuclear Model
Who discovered the nucleus and proton?
Ernest Rutherford
Who named proton?
Eugene Goldstein
It used the gold foil experiment or the bouncing back of alpha particles
Nuclear model
Who discovered the neutron?
James Chadwick
It is a discovery about how the electrons orbit the nucleus
Bohr’s Planetary Model
Bohr’s Planetary Model states that _____ is related to its _____.
(The smaller the orbit ring, the lower the energy)
energy, size
He stated that atoms are solid, uniform, incompressible, and indestructible.
Democritus
It states that the position of electron and momentum are impossible to determine at the same time since electrons are moving in a greater speed, but there is a probability to locate the electron.
Uncertainty Principle
Who is behind the uncertainty principle?
Werner Heisenberg
What is diamagnetic?
All electrons are paired and it is not affected by the magnetic field.
What is paramagnetic?
There are unpaired electrons and it is affected by the magnetic field.
What are the 3 rules in determining the lowest energy arrangement?
Aufbau Principle, Pauli Exclusion Principle, and Hund’s Rule
States that electrons fill first the orbitals of the lowest energy (ground state) until any added electrons occupy the available orbital of the higher energy (excited state).
Aufbau Principle
States that no more than two electrons in an atom can occupy an orbital and they must spin in the opposite direction.
Pauli Exclusion Principle
States that for a set of orbitals, electrons occupy orbital of equal energy (electrons enter each orbit with parallel spin, then a second electron will be added pairing the first electrons with an opposite spin.
Orbital diagram - Arrange the first arrows in an upward direction first.
Hund’s Rule
