So how am I supposed to remember the order of the rooms? 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 8 46 total e - Pd orbitals? Noble Gas Notation = [Kr] 5s 2 4d 8

If e - don’t really stay in hotel rooms… CORRECT VOCABULARY Floor = Principal Energy Level Suite = Sublevel Room = Orbital 3s 2p 2s 1s 1s 2 2s 1 Li

Maximum Number of Electrons In Each Sublevel Maximum Number of Electrons In Each Suite Type Suite # of Maximum # Type rooms of electrons s 1 2 p 3 6 d 5 10 f 7 14 Sublevel orbitals

11/17/14 CHEMISTRY MRS.TURGEON “ Students need to learn how to think critically, how to argue opposing ideas. It is important for them to learn how to think. You can always cook. Charlie Trotter OBJECTIVES SWBAT: 1.Describe how light can be used to identify substances DO NOW: 1. Which is a higher energy level in an atom: n=1 or n=5?

11/24/14 CHEMISTRY MRS.TURGEON “Find something you're passionate about and keep tremendously interested in it.” ---Julia Child OBJECTIVES SWBAT: 1.Define ionization energy DO NOW: 1. If I know the frequency of a wave, what is the equation (rearranged) that I would use to solve for the wavelength?

11/24/14 CHEMISTRY MRS.TURGEON Reminders: 1. Quiz today on Light POGIL/Light equations 2. Science/Environmental Club will meet today after school.

11/19/14 CHEMISTRY MRS.TURGEON Today’s Activity: 1. In your textbook: Complete numbers 1-4 on pg. 140 and 5-7 on page Turn in one paper with all group names, but each student needs to have their own copy for their notes 3. Make sure you show all work with the rearranged equation when applicable

Excitation of Hydrogen Atoms

Return to Ground State

An Excited Lithium Atom Photon of red light emitted Li atom in lower energy state Excited Li atom Energy

Chemist Humor Question: Why does hamburger have lower energy than steak? Answer: Because it’s in the ground state.

The Electromagnetic Spectrum (BIG FANCY WORDS FOR.... LIGHT)

Visible part of EM SPectrum PRISM Slit Ray of White Light Waves 1 / 33,000 ” long Waves 1 / 70,000 ” long R ed O range Y ellow G reen B lue I ndigo V iolet 400 nm – 700 nm

BIG topics...copy these down  Light (electromagnetic radiation)  particle/wave dual nature of light  c, λ, ט, E & h  Quantum vs. Photon (p. 128, p.144)  Quantum theory (wave mechanical model)  Bohr model of atom (ENERGY LEVELS)  Atomic absorption/emission & spectra  Orbital shapes & Heisenberg uncertainty  Electron configurations  orbital, e - configuration  noble gas notation  Aufbau, Pauli, & Hund

Waves  Wavelength ( ) - length of one complete wave. Common units: m or nm  Frequency ( ) - # of waves that pass a point during a certain time period (usually per second) Common Units: hertz (Hz) = 1/s = s -1  Amplitude (A) - distance from the origin to the trough or crest (height of one wave) Courtesy Christy Johannesson

Frequency O’Connor, Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles  1982, page second Frequency 4 cycles/second = 4 hertz 12 cycles/second = 12 hertz 36 cycles/second = 36 hertz

Vocabulary of a Wave Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 324 A c = speed of light = x 10 8 m/s (really fast, true for every kind of light!)

Continuous and Line Spectra light Na H Ca Hg nm Visible spectrum  (nm)

Flame Test Emission Spectra Photographs of flame tests of burning wooden splints soaked in different salts. methane gas wooden splintstrontium ioncopper ionsodium ion calcium ion

Copyright © 2006 Pearson Benjamin Cummings. All rights reserved.

Example: Emission Spectrum of Hydrogen 1 nm = 1 x m = “a billionth of a meter” 410 nm434 nm486 nm656 nm ATOMIC SPECTRA: See p. 141 before Friday!

Other Elements  Each element has a unique bright-line emission spectrum. i.e. “Atomic Fingerprint” Helium zBohr’s calculations only worked for hydrogen!  Courtesy Christy Johannesson

Wave-Particle Duality JJ Thomson won the Nobel prize for describing the electron as a particle. His son, George Thomson won the Nobel prize for describing the wave-like nature of the electron. The electron is a particle ! The electron is an energy wave!

The Wave-like Electron Louis deBroglie The electron propagates through space as an energy wave. To understand the atom, one must understand the behavior of electromagnetic waves.

Quantum Theory Max Planck (1900) ‏  Observed - emission of light from hot objects  Concluded - energy is emitted in small, specific amounts (quanta) ‏  Quantum - minimum amount of energy gained or lost by an atom Courtesy Christy Johannesson

Electromagnetic Radiation = PHOTONS Light as a wave Light as a stream of energy (packets of photons) Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 325

IMPORTANT LIGHT EQUATION #1  Frequency & wavelength are inversely proportional c = c:speed of light (2.998  10 8 m/s) :wavelength (m, nm, etc.) :frequency (Hz or s -1 ) Courtesy Christy Johannesson

Example Problem for Equation #1 Find the frequency in Hertz of microwave radiation with a wavelength of 7.5  m. GIVEN: = ? = 7.5  m c =  10 8 m/s WORK: = c  =  10 8 m/s 7.5  m = 4.0 x s-1 = 4.0 x Hz Courtesy Christy Johannesson

IMPORTANT LIGHT EQUATION #2 E:energy (J, joules) h:Planck’s constant (  J·s) :frequency (Hz) E = h The energy of a photon is proportional to its frequency. Courtesy Christy Johannesson

Energy of Waves – It takes more energy to travel at a higher frequency… Low frequency High frequency, short wavelength Amplitude Low frequency, long wavelength short wavelength 

Red and Blue Light Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 325 Photons - particle of light that carries a quantum of energy

Example problem for Equation #2 Find the energy of a red photon with a frequency of 4.57  Hz. GIVEN: E = ? = 4.57  Hz h =  J· s WORK: E = h E = (  J· s ) ( 4.57  Hz ) E = 3.03  J Courtesy Christy Johannesson

Example problem using BOTH Equations… Find the energy of a photon with a wavelength of 1.0 x nm. GIVEN: h  x J s c = 3.00 x 10 8 m/s = ? = 1.0 x nm = ???? m WORK: = c = 3.00  10 8 m/s 1.0 x m = 3.0 x s -1 E = hv c = λv  = (6.626 x J s)(3.0 x s -1 ) E = 1.99 x J

Equations with Wavelength and Frequency E = h c =  c = speed of light (2.998 x 10 8 m/s)‏ = frequency (s -1 )‏  = wavelength (m)‏ E = energy (Joules or J)‏ h  = Planck’s constant (6.626 x J s)‏ = frequency (s -1 )‏ “nu” “lamda” Highest energy Moderate energy Lowest energy

Common wavelength units for electromagnetic radiation Picometer pm Gamma ray Ångstrom Å X-ray Nanometer nm X-ray Micrometer  m Infrared Millimeter mm Infrared Centimeter cm Microwave Meter m 10 0 Radio Unit Symbol Wavelength, (m) Type of Radiation Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.

Bohr Model of Hydrogen Nucleus Possible electron orbits e Further away from nucleus means higher energy level…

Bohr Model electrons exist only in orbits with specific amounts of energy called energy levels Therefore… electrons can only gain or lose certain amounts of energy only certain photons are produced Courtesy Christy Johannesson

Orbital Shapes Orbital Shapes

e-e- e-e- Ground state Excited state Electrons can only be at specific energy levels, NOT between levels.

Continuous vs. Quantized Energy Energy A B continuous quantized A continuous B quantized

Bohr Model  Energy of photon depends on the difference in energy levels  Bohr’s calculated energies matched the IR, visible, and UV lines for the H atom Courtesy Christy Johannesson nucleus

Frequency A Frequency B Frequency C n = 2 n = 1 n = 3 A B C A + B = C

Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.