Atomic Structure Flashcards
what was the first atomic model and who proposed it?
solid sphere model, by Dalton
What was the second atomic model and who proposed it?
plum pudding model by JJ Thomson
what was the third atomic model and who proposed it?
the nuclear model by Rutherford
what was the fourth atomic model and who proposed it?
planetary model by Bohr
what was the fifth atomic model and who proposed it
the quantum model by Schrodinger
quantum mechanics
the study of motion at the atomic level where classical lawss of motions do not apply because the particles behave like waves
what did de Broglie think?
orginated the idea than an electron has both wave and particle properties
what demo did Schrodinger and de Broglie perform?
standing wave demo
What did Schrodinger and de Broglie find with the electron from hydrogen?
the model showed the electron as a circular stading wave ith wavelenths of whole number multiples
how did other orbits affect the standing wave?
would cause it to cancel out or collapse
orbital
a region around the nucleus where there is a high probability of finding an electron
what did the Schrodinger wave equation lead to?
can be used to calculate electron energy levels, which gives a definable amount of energy to an electron allowing it to be localized to a given orbital
Heisenbergs uncertainty principle
the idea that it is impossible to know the exact position and speed of an electron and the same given time
electrons are so small that any attempt to measure its location or speed will affect its location and/or speed
what are the two main points of the quantum mechanical model?
- electrons can be in different orbitals by absorbing or emitting quanta of energy
- the location of electron is given by a probability distribution
electron configuration
shows the specific placement of electrons within an energy level
sublevel of an energy level called:
orbital
how many electrons can orbital hold?
a maximum of 2
what are the 4 types of orbitals??
s, p, d, f,
(sharp, principal, diffuse, and fundamental)
how many s orbitals?
single
how many p orbitals?
groups of 3
how many d orbitals?
groups of 5
how many f orbitals?
groups of 7
where are s orbitals found?
on every energy level
where are p orbitals found?
at energy level 2 and above
where are d orbitals found?
energy levels 3 and above
where are d orbitals found?
in energy levels 3 and above
where are f orbitals found?
levels 4 and above
in what order are electrons placed in energy levels?
from lowest enegy (closest to the nucleus) to highest energy
Pauli Exclusion principle
when 2 electrons are placed in the same orbital, these electrons will spin in different directions (one arrow points up and another points down)
Aufbau pinciple
lowest energy orbitals are filled first
Hund’s rule
when there are multiple orbitals of equal energy, each orbitals gets a single elerctron before pairing up electrons
describe longhand configuration
writing the lowest energy level and orbital type and put the number of electrons as a superscript for the orabital then conitnue until all electrons have been accounted for
describe shorthand or noble gas configuration
use the closest noble gas with fewer electrons, place that symbol is square brackets and resume the configuration and continue until all electrons have been accounted for
what are the 2 stable electron configurations
a filled set or orbitals or a half filled set of orbitals
Which elements are exceptions to the rule?
Cr, Mo, Cu, Ag, Au
how does Cr differ from normalcy?
[Ar]4s13d5 NOT [Ar]4s23d4
since it is more stable and takes less energy for the 4s and 3d orbitals to be half filled
describe the electron configuration of negative ions
negative ions will gain enough electrons to fill the orbitals of their highest energy level. Non-metals make anions so they would be P orbitals that are the highest energy shells
describe the electron configuration of positive ions
will lose electrons from the highest avaible energy shell before it loses from the next shell down
quantum numbers
set of 4 numbers that describe an electron’s location
whats the first number?
principal quantum number (n), the energy level the electron is in
what is the second quantum number
secondary quantum number (l), describes sublevel (orbital type)
s= 0
p = 1
d = 2
f = 3
aka angular momentum quantum number
what is the third quantum number?
magnetic quantum number (m)
descibes which orbital the sublevel electron is in
what is the fourth quantum number?
spin quantum number
describes whether electron is spinning clockwise (+1/2) or counterclockwise (-1/2)
Who discovered the electron?
J.J Thomson Joseph john
How was the electron discovered?
With the cathode ray experiment. Electric current run through a glass tube a stream of negatively charged particles was emittey
Who discovered the nucleus?
Rutherford
How was the nucleus discovered?
With the gold foil experiment
Who discovered the neutron?
James Chadwick
