1. Schrodinger model for the atom (1926)
the 3D wave shapes (orbitals) describe the places in space
where the electrons can be
they are nothing physical
(the orbital is not a paved road…)
but equal the probability of
finding an electron at a particular
point in the particular 3D space
Just like for Bohr…. once Bohr had the orbits,
he could calculate the energy of an electron in the orbit….
once Schrodinger had the orbitals,
he could calculate the energy of an electron in the orbitals…

2. how close the electron is to the nucleus
Energy of Orbitals
the energy (stability) of an electron in an orbital will depend on…
what is holding the electron?
____________________________
what will increase the strength of this attraction?
_____________________________
depends on _______________________
depends on _____________
and ___________________
the nucleus
how close the electron is to the nucleus
the size of the orbital
n (quantum number)
Z (the # of protons)
(the type of atom)
as n goes ___
the size of the orbital ______
on average the electron is ________ from the nucleus
so,
__________ stable
__________ in energy UP
goes UP
further
less
higher

3. Atomic orbitals in order of increasing energy
(for single electron particles… like H) 5f 5p 5s 5d 4f 4p 4s 4d 3p 3s 3d 2p 2s 1s
n / Energy 5g
For Hydrogen
(and any other one electron particle),
all the orbitals with the same value of n
are at the same energy

4. Ground state electron configurations of atoms of the elements
distribution of the e- of an atom in the orbitals
(arrangement)
Most
stable
Electrons as close to the nucleus as possible
NOTE, the e- can be in any of
the infinite # of orbitals,
but one arrangement will be the
most stable – ground state
Aufbau Principle
- electrons will occupy the lowest energy
(closest to the nucleus) orbital available

5. Atomic orbitals in order of increasing energy
(for single electron particles… like H) 5f 5p 5s 5d 4f 4p 4s 4d 3p 3s 3d 2p 2s 1s 5g
Hydrogen – atomic # (Z) = 1
means ?
1 proton in the nucleus
n / Energy
so, a neutral atom will have
___electron(s) ? 1
into which orbital will that
electron “go” to be most stable?
the orbital 1s
ground state electron configuration: e-
1s 1

6. Atomic orbitals in order of increasing energy
(for single electron particles… like H) 5f 5p 5s 5d 4f 4p 4s 4d 3p 3s 3d 2p 2s 1s
n / Energy 5g
Hydrogen – atomic # (Z) =
1s 1
ground state electron configuration:
excited state ?
how does the excited state happen? e-

7. Atomic orbitals in order of increasing energy
(for single electron particles… like H) 5f 5p 5s 5d 4f 4p 4s 4d 3p 3s 3d 2p 2s 1s
n / Energy 5g e-
Hydrogen – atomic # (Z) = 1
1s 1
ground state electron configuration:
excited state electron configuration:
4p 1 h h h e-
ultraviolet

8. Atomic orbitals in order of increasing energy
(for single electron particles… like H) 5f 5p 5s 5d 4f 4p 4s 4d 3p 3s 3d 2p 2s 1s
n / Energy 5g e- e-
Hydrogen – atomic # (Z) = 1
excited state electron configuration:
excited state electron configuration:
4p 1 h
2p 1

9. e- Atomic orbitals in order of increasing energy
(for single electron particles… like H) 5f 5p 5s 5d 4f 4p 4s 4d 3p 3s 3d 2p 2s 1s
n / Energy 5g
Helium – atomic # (Z) = 2
means ?
2 protons in the nucleus
where do I go !??
so, a neutral atom will have
___electrons ? 2 e-
Before we can consider where the two electrons “go”,
we first need to consider
the effect of electrons on electron stability….. e- e-

10. so … the nucleus how close the electron is to the nucleus
Energy of Orbitals
the energy (stability) of an electron in an orbital will depend on…
what is holding the electron?
____________________________
what will increase the strength of this attraction?
_____________________________
depends on _______________________
depends on _____________
and ___________________ 1.
the nucleus
how close the electron is to the nucleus
the size of the orbital
so …
n (quantum number)
Z (the # of protons)
(the type of atom) 2.
what else (besides the nucleus) will effect the stability (energy)
of an electron… ?
____________________________________
because
so,
the presence of other electrons
electrons repel each other
electrons “want” to be as far from each other as possible

11. CLOSE FAR ATTRACTIONS REPULSIONS
Energy of Orbitals
so, ….
electrons “want” to be as _______________ to the nucleus as possible
AND
as ______________ from other electrons as possible
the electrons arrange themselves to “find a balance” between
the _______________________ to the nucleus
and
the _______________________ from other electrons
CLOSE
FAR
ATTRACTIONS
REPULSIONS
the consequence of this “push me pull you”
is that the energy of the atomic orbitals shift a bit…
resulting in…

12. on to electron_configurations_2