Orbitals
Do now:
What do we mean
by an energy
level?
How do we know
where an electron
is?
Electron orbitals
● Schrödinger: wave equation, when applied to electron
systems produces orbitals.
● These are the regions around an atomic nucleus in
which there is a 90% probability of finding the electron.
● The shape will depend on the energy of the electron.
● Higher energy has a higher probability of being further
away from the nucleus.
The Bohr Model
A one-dimensional model, one quantum number (n) to
describe the distribution of electrons in the atom.
Schrödinger’s model
• Electrons occupy three-dimensional space.
• Three coordinates, or three quantum numbers, to describe the
orbitals in which electrons can be found that come from wave
equations.
Quantum electron configuration
Principal (n): describes the size of the orbital.
•Electrons are attracted to the nucleus of the atom.
Quantum electron configuration
Angular (ℓ): describes the shape of the orbital.
• Orbitals have shapes that are best described as spherical (ℓ = 0), polar
(ℓ = 1), or cloverleaf (ℓ = 2).
• They can even take on more complex shapes as the value of the
angular quantum number becomes larger.
Quantum electron configuration
Magnetic (m): describes the orientation in space
• There is only one way in which a sphere (ℓ = 0) can be oriented in
space.
• (It is called the magnetic quantum number because the effect of
different orientations of orbitals was first observed in the presence of a
magnetic field)