10/14/14
1
Warm Up ! Lots of handouts
! Turn in Flame test Lab
! Orbital shapes worksheet (do it now)
! New ConnectED assignment after today
Agenda ! Worksheet: Orbital shapes
! Review: Quantum numbers (PAP) (Quiz next class)
! Whiteboards: Quantum numbers practice (PAP)
! Coloring: periodic table – s, p, d, f
! Notes: Electron configurations (quiz next class)
! Whiteboards: energy level diagrams practice
! Worksheet: energy level diagrams
! Whiteboards: orbital diagrams and electron configurations
! Homework: orbital diagrams and electron configurations
Objective ! express the arrangement of electrons in atoms
through electron configurations
Electron Configurations
Where are the e-‐s in an atom? Quantum numbers can tell us
! Quiz over these next time
! e-‐ “address”
! 4 of ‘em ! Principle Quantum
Number
! Angular Momentum Quantum Number
! Magnetic Quantum Number
! Spin Quantum Number
Principle Quantum Number (n)
! Same as “energy levels” in Bohr model
! Tells you how far from nucleus electron is
! Can be integers from 1 to ∞
! An energy level has n2 orbitals
10/14/14
2
Angular Momentum Quantum Number (l )
! Tells you shape of orbital electron is in
! Also called “sublevel”
! Integers from 0 to n-‐1
! Shapes are: ! l = 0 ; s (sphere) ! l = 1 ; p (dumbbell)
! l = 2 ; d (clover) ! l = 3 ; f (goofiness)
! # of orbitals in each: ! s=1, p=3, d=5, f=7
Atomic'Orbitals'
'
Orbital shapes
Magnetic Quantum Number (ml ) ! Tells you which orbital within a sublevel electron is in
! Integers from –l to +l
! –l ≤ m ≤ +l
! Orbitals can only hold up to 2 electrons
2s
2pz 2py 2px
Spin Quantum Number (ms) ! Orbitals can only hold up to 2 electrons
! Those 2 electrons must spin in opposite directions (pauli exclusion principle)
! Options are +½ and −½
A quantum nut shell 1. Principal # → 2. Ang. Mom. # → 3. Magnetic # → 4. Spin # →
energy level sublevel (s,p,d,f) orbital electron
Quantum Number Practice
! Go to other powerpoint
10/14/14
3
How do we document electrons?
! Every neutral atom has an equal number of protons and electrons (1 negative for every positive charge)
! So, for most atoms writing the quantum #s for every e-‐ would take forever
! Therefore, we created a shorthand way to do it
! It’s called an “electron configuration”
! Electron configurations (e configs.) tell us the position (“address”) of every electron in an atom
! In order to understand e configs, let’s look at a model that can help us visualize where e-‐s hang out
Energy Level Diagrams ! Each box is an orbital
! Orbitals can only hold up to 2 electrons
! We use the letters to write sublevels instead of numbers
!
Correlation b/w Ptable & Orbitals 3 Rules for filling orbitals
! Pauli Exclusion Principle
! Aunau Principle
! Hund’s Rule
Pauli Exclusion Principle ! No 2 electrons can have the same 4 quantum numbers
! So, any 2 electrons occupying the same orbital (having the same n, l, and ml) must have opposite spins
! We denote this using up and down arrows
Aunau Principle
! “building up”
! Electrons fill the lowest energy orbitals first
10/14/14
4
Aunau order Aunau order
Hund’s Rule ! every orbital in a subshell is singly occupied with one electron
before any one orbital is doubly occupied, and all electrons in singly occupied orbitals have the same spin
Energy Level Diagram practice
Orbital Filling Sequence ! Use what you’ve learned and the orbital filling
sequence diagram to answer the questions on the orbital filling sequence worksheet
Orbital diagrams are flat energy level diagrams
10/14/14
5
Electron configurations are orbital diagrams with numbers instead of arrows
for electrons
! 1s22s22p4 ! Electron configuration for oxygen
Noble gas configurations ! Abbreviated electron configurations
! Noble gasses are the right-‐most column (family)
! Since electron configurations read like a book on the periodic table, we can just write the element at the end of the previous row (period) and continue from there
! [He] 2s22p4 ! Noble gas configuration for oxygen
Correlation b/w Ptable & Orbitals Valence Electrons
Octet rule Neutral Atoms vs. Ions
Top Related