Download Electrons

Electrons
 Studied the nucleus of the atom
 Focused on the electrons and where they are
found.
 Called the orbital model
Niels Bohr
 Electrons can move between energy levels
 Energy must be supplied to the electrons to
have them change levels
 High voltage electricity or radiation
Bohr Model
 When electrons return to their original level
they give off light depending on the
wavelength
Energy Levels
Each energy level can be broken down
into smaller levels called sublevels.
Each sublevel can be broken down into
smaller levels called orbitals.
The orbitals have the highest probability
of finding an electron
Energy Levels
Energy levels can be thought of as the
rungs on a ladder.
The number of the energy level tells you
how many sublevels there are.
 Energy level 1 has 1 sublevel, energy level 2
has 2 sublevels, and so on
The 1st sublevel is the “s” level, the 2nd is
the “p” , the 3rd is the “d”, and the 4th is
the “f”
Each sublevel has a different number of
orbitals
Orbitals
 S has 1 orbital
 P has 3 orbitals
 D has 5 orbitals
 F has how many orbitals?
Each orbital can hold exactly 2 electrons
Energy Levels
Principle Level
(n)
Sublevels (n)
# of orbitals (n2)
# of electrons
(2n2)
1
1s
1
2
2
2s
2px, 2py, 2pz
1
3
8
3
3s
3px, 3py, 3pz
3d
1
3
5
18
4
4s
4px, 4py, 4pz
4d
4f
1
3
5
7
32
Orbital Shapes
Orbital Shapes
Orbital Shapes
Electron
Configuration
Shows the electron arrangement in an
atom.
Always represents the lowest possible
energy.
Always start by filling the lowest energy
levels first
 Called the Aufbau Principle
Example
Write the electron configurations for the
following elements:
Practice
 Beryllium
 Neon
 Sodium
 Phosphorus
 Calcium
Shorthand
Method
Shorthand notation uses the noble gases
as a reference point
Example: Ge [Ar] 4s23d104p2
Rewrite the practice elements from the
previous slide using the shorthand
notation.
 Can make a diagram to show electron
configurations
 Must follow Hund’s Rule for filling out orbital
diagrams
Orbital
Diagrams
 Hund’s Rule – all orbitals in a sublevel must have
one electron in them before doubling up
 When placing the arrows in an orbital, one
must face up the other must face down.
Draw orbital diagrams for the following
elements:
Practice
 Silicon
 Nickel
 Chlorine
 Helium
Relative
Energies of
Orbitals