Orbital Notation and Electron Configuration October 20th
Jan 04, 2016
Orbital Notation and
Electron Configuration
Orbital Notation and
Electron Configuration
October 20thOctober 20th
Distance From The NucleusDistance From The Nucleus
Called the Principle Quantum Number (n)
Describes the principle energy leveln = 1, 2, 3
Called the Principle Quantum Number (n)
Describes the principle energy leveln = 1, 2, 3
Shape of the OrbitalShape of the Orbital
Described by Orbital quantum number (l)
Tells you the shape of the orbital the electron is in
Is it an s, p, d, or f orbital?
Described by Orbital quantum number (l)
Tells you the shape of the orbital the electron is in
Is it an s, p, d, or f orbital?
Position in 3D SpaceDescribed by Magnetic Quantum Number (m)Indicated the position of the orbital around the 3
axes (x, y, z)
Electron’s Spin
The direction of the electron’s spin is described by the spin quantum number
Electrons can be either up or downWhen electrons are part of a pair, they
must spin in opposite directions
Pauli Exclusion PrinciplePauli Exclusion PrincipleNo two electrons in the same atom can
have the same four quantum numbers (the same description)
No two electrons can have the same address
Electrons are repulsed by each other, so they cannot live together… Hence makes sense they have opposite spins!
No two electrons in the same atom can have the same four quantum numbers (the same description)
No two electrons can have the same address
Electrons are repulsed by each other, so they cannot live together… Hence makes sense they have opposite spins!
Review Of Energy LevelsReview Of Energy Levels
n = 1s orbital (2 electrons)
n = 2s orbital (2 electrons)p orbital (6 electrons)
n = 3s orbital (2 electrons)p orbital (6 electrons)d orbital (10 electrons)
n = 4s orbital (2 electrons)p orbital (6 electrons)d orbital (10 electrons)f orbital (14 electrons)
n = 1s orbital (2 electrons)
n = 2s orbital (2 electrons)p orbital (6 electrons)
n = 3s orbital (2 electrons)p orbital (6 electrons)d orbital (10 electrons)
n = 4s orbital (2 electrons)p orbital (6 electrons)d orbital (10 electrons)f orbital (14 electrons)
3 Rules for Electron Configuration3 Rules for Electron Configuration
1) Aufbau Principle - electrons occupy the orbitals of lowest energy first
2) Pauli Exclusion Principle - no two electrons can have the same address(same 4 quantum #s)
3) Hund’s Rule - Electrons try to occupy different orbitals before pairing up
1) Aufbau Principle - electrons occupy the orbitals of lowest energy first
2) Pauli Exclusion Principle - no two electrons can have the same address(same 4 quantum #s)
3) Hund’s Rule - Electrons try to occupy different orbitals before pairing up
Orbital Notation
order in which electrons are filled
Orbital Notation
order in which electrons are filled
The Order in which orbitals fill…The Order in which orbitals fill…
Orbital NotationOrbital Notation
Arrowsdepictelectronspin
ORBITAL BOX NOTATIONfor He, atomic number = 2
1s
21 s
Arrowsdepictelectronspin
ORBITAL BOX NOTATIONfor He, atomic number = 2
1s
21 s
Arrangement of Arrangement of Electrons in AtomsElectrons in AtomsArrangement of Arrangement of Electrons in AtomsElectrons in Atoms
Each orbital can be assigned no more than 2 Each orbital can be assigned no more than 2 electrons!electrons!
Each orbital can hold a pair of electrons per Each orbital can hold a pair of electrons per orientationorientationss 1 orientation(pair)1 orientation(pair) 2 electrons 2 electrons pp 3 orientations3 orientations 6 electrons 6 electronsdd 5 orientations5 orientations 10 electrons 10 electronsff 7 orientations7 orientations 14 electrons 14 electrons
Each orbital can be assigned no more than 2 Each orbital can be assigned no more than 2 electrons!electrons!
Each orbital can hold a pair of electrons per Each orbital can hold a pair of electrons per orientationorientationss 1 orientation(pair)1 orientation(pair) 2 electrons 2 electrons pp 3 orientations3 orientations 6 electrons 6 electronsdd 5 orientations5 orientations 10 electrons 10 electronsff 7 orientations7 orientations 14 electrons 14 electrons
Orbital Diagram
_____ 1s
_____ _____ _____ _____ 2s 2px 2py 2pz
_____ _____ _____ _____ _____ _____ _____ _____ _____ 3s 3px 3py 3pz 3d
_____ _____ _____ _____ _____ _____ _____ _____ _____ 4s 4px 4py 4pz 4d
_____ _____ _____ _____ _____ _____ _____ _____ _____ 5s 5px 5py 5pz 5d
_____ 6s
How Orbitals Fill….How Orbitals Fill….
_____ 1s
_____ _____ _____ _____ 2s 2px 2py 2pz
_____ _____ _____ _____ 3s 3px 3py 3pz
Electron Configuration – StrontiumElectron Configuration – Strontium
_____ 1s
_____ _____ _____ _____ 2s 2px 2py 2pz
_____ _____ _____ _____ _____ _____ _____ _____ _____ 3s 3px 3py 3pz 3d
_____ _____ _____ _____ _____ _____ _____ _____ _____ 4s 4px 4py 4pz 4d
_____ _____ _____ _____ _____ _____ _____ _____ _____ 5s 5px 5py 5pz 5d
_____ 6s
Valence electrons are electrons in the outermost energy level of an atom.
_____ 1s
_____ _____ _____ _____ 2s 2px 2py 2pz
_____ _____ _____ _____ 3s 3px 3py 3pz
Valence electrons
Example: Sulfur
Practice on your own!Practice on your own!Draw the orbital diagram for Calcium
Draw the orbital diagram for Silicon
Draw the orbital diagram for Calcium
Draw the orbital diagram for Silicon
Electron ConfigurationElectron Configuration
11 s
Energy LevelSubshell(s, p, d, f)
no. of
electrons
for H, atomic number = 1
Electron ConfigurationElectron ConfigurationFortunately! Its like orbital diagrams but
without drawing the orbitals…
Fill electrons into lower energy levels firstFollow order of fillingRemember how many electrons each level can
hold: s holds 2, p holds 6, d 10, f 14
Fortunately! Its like orbital diagrams but without drawing the orbitals…
Fill electrons into lower energy levels firstFollow order of fillingRemember how many electrons each level can
hold: s holds 2, p holds 6, d 10, f 14
ExamplesExamplesHelium: 1s2
Boron : 1s22s22p1
Magnesium: 1s22s22p63s2
Bromine: 1s22s22p63s23p64s23d104p5
Helium: 1s2
Boron : 1s22s22p1
Magnesium: 1s22s22p63s2
Bromine: 1s22s22p63s23p64s23d104p5
1s1
1s22s22p63s1
1s22s22p63s2
1s22s22p63s23p5
1s22s22p63s23p6
1s22s22p63s23p64s23d104p3
Practice on your own!
Hydrogen
Sodium
Magnesium
Chlorine
Argon
Arsenic
Octet rule - all elements want to have a full set of valence electrons
Atoms will lose or gain electrons in trying to achieve a full octet
Octet rule - all elements want to have a full set of valence electrons
Atoms will lose or gain electrons in trying to achieve a full octet
Octet Rule
Octet Rule states that atoms will gain or lose electrons to achieve a full outermost energy level.
This is usually 8 electrons (s2 p6).
Example: Oxygen
_____ 1s
_____ _____ _____ _____ 2s 2px 2py 2pz
O
Octet Rule