Electron Orbits Pick-up Sheets on the Table Orbit Notes Orbit cut-outs in notebook

Quantum Mechanics zHeisenberg Uncertainty Principle  Impossible to know both the velocity and position of an electron at the same time

Quantum Mechanics Radial Distribution Curve Orbital zOrbital (“electron cloud”)  Region in space where there is 90% probability of finding an e -

Quantum Numbers zFour Quantum Numbers:  Specify the “address” of each electron in an atom

Pauli Exclusion Principle No two electrons in an atom can have the same four quantum numbers. Wolfgang Pauli

Quantum Numbers 1. Principal #  2. Ang. Mom. #  3. Magnetic #  4. Spin #  energy level sublevel (s,p,d,f) specific orbital electron zPauli Exclusion Principle  No two electrons in an atom can have the same 4 quantum numbers.  Each e - has a unique “address”:

Quantum Numbers 1. Principal Quantum Number ( n )  Energy level  Size of the orbital  n 2 = # of orbitals in the energy level

Principal Quantum Number Generally symbolized by n, it denotes the shell (energy level) in which the electron is located. Number of electrons that can fit in a shell: 2n 2

Quantum Numbers s p d f 2. Angular Momentum Quantum # ( l )  Energy sublevel  Shape of the orbital

S orbit zSphere zHold 2 Electron in 1 orbit

P Orbit zDumbell Shape zHold 2 electrons in 3 orbits zTotal of 6 Electrons

d-orbital zX shape z5 orbitals that hold 2 electrons each z10 total e-

F-orbital zFlower Shape z7 orbitals that hold 2 electrons each z14 total electrons

C. Johannesson Quantum Numbers 3. Magnetic Quantum Number ( m or m l ) yOrientation of orbital ySpecifies the exact plane that the orbit is on

Quantum Numbers 4. Spin Quantum Number ( m s ) Electron spin  +½ or -½ An orbital can hold 2 electrons that spin in opposite directions.

C. Johannesson

Configuration Notes Configuration Practice Electron Configurations

Orbital filling table

C. Johannesson s-block1st Period 1s 1 1st column of s-block Periodic Patterns zExample - Hydrogen

Electron configuration of the elements of the first three series

Steps to Writing Electron Configuration z1. Determine the # of electrons z2. Use the redesigned PT to get the configuration z3. Superscripts will equal the electrons

C. Johannesson © 1998 by Harcourt Brace & Company s p d (n-1) f (n-2) Periodic Patterns

C. Johannesson zShorthand Configuration S 16e - Valence Electrons Core Electrons S16e - [Ne] 3s 2 3p 4 1s 2 2s 2 2p 6 3s 2 3p 4 Notation zLonghand Configuration

C. Johannesson [Ar]4s 2 3d 10 4p 2 Periodic Patterns zExample - Germanium

Orbital Notation - shows the position of each electron in the orbitals Use the electron Configuration z1. draw boxes for the sublevel… 1 for s, 3 for p, 5 for d and 7 for f. z2. Fill the orbits with arrows to represent electrons.

C. Johannesson A. General Rules zPauli Exclusion Principle yEach orbital can hold TWO electrons with opposite spins.

C. Johannesson A. General Rules zAufbau Principle yElectrons fill the lowest energy orbitals first.

C. Johannesson RIGHT WRONG General Rules zHund’s Rule Within a sublevel, place one e - per orbital before pairing them.

C. Johannesson O 8e - zOrbital Diagram zElectron Configuration 1s 2 2s 2 2p 4 Notation 1s 2s 2p

zH zLi zC zF zNe zP zMn Examples