do now… draw the diagram that reminds you of the correct order of electron orbitals. write out the...

DO NOW…

Draw the diagram that reminds you of the correct order of electron orbitals.

Write out the electron configuration for Pd in full form and in noble gas notation

Homework = Read 5.3 AGAIN & #’s 16-18,21,42,44-47

So how am I supposed to remember the order of the rooms?

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2

4d8

46 total e-

Pd

orbitals?

Noble Gas Notation = [Ar] 5s24d8

If e- don’t really stay in hotel rooms…

CORRECT VOCABULARY

Floor = Principal Energy Level

Suite = Sublevel

Room = Orbital

3s

2p

2s

1s1s22s1Li

Review....Orbital ShapesReview....Orbital Shapes

Maximum Number of Electrons In Each SublevelMaximum 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

Sublevel orbital

s

Excitation of Hydrogen Atoms

Return to Ground State

An Excited Lithium Atom

Photon ofred lightemitted

Li atom inlower energy state

Excited Li atom

Ene

rgy

Chemist Humor

Question:Question: Why does hamburger have lower energy than steak?

Answer:Answer: Because it’s in the ground state.

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

Visible part of EM Visible part of EM SPectrumSPectrum

PRISM

Slit

Ray of

White Light

Waves 1/33,000” long

Waves 1/70,000” long

RedOrangeYellowGreenBlueIndigoViolet

400 nm – 700 nm

BIG topics...copy these down Light (electromagnetic radiation) particle/wave dual nature of light c, λ, ט , E & hQuantum vs. Photon (p. 128, p.144)

Quantum theory (wave mechanical model)Bohr model of atom (ENERGY LEVELS)Atomic absorption/emission & spectraOrbital shapes & Heisenberg uncertainty

Electron configurationsorbital, e- configuration noble gas notationAufbau, 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)

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Frequency

O’Connor, Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles 1982, page 166

1 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 = 2.998 x 10 8 m/s

(really fast, true for every kind of light!)

Quantum TheoryQuantum 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

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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 (2.998 108 m/s): wavelength (m, nm, etc.): frequency (Hz or s-1)

Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

Example Problem for Equation #1

Find the frequency in Hertz of microwave radiation with a wavelength of 7.5 10-3 m.

GIVEN:

= ? = 7.5 10-3 mc = 2.998 108 m/s

WORK: = c

= 2.998 108 m/s

7.5 10-3 m

= 4.0 x 1010 s-1

= 4.0 x 1010 HzCourtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

IMPORTANT LIGHT EQUATION #2

E: energy (J, joules)h: Planck’s constant (6.6262 10-34 J·s): frequency (Hz)

E = h

• The energy of a photon is proportional to its frequency.

Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

Energy of Waves – It takes more energy to travel at a higher frequency…

Low frequency

High frequency, short wavelength

Amplitude

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 1014 Hz.

GIVEN:

E = ? = 4.57 1014 Hzh = 6.6262 10-34 J· s

WORK:

E = h

E = (6.6262 10-34 J· s) (4.57 1014 Hz)

E = 3.03 10-19 J

Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

Example problem using BOTH Example problem using BOTH Equations…Equations… Find the energy of a photon with a

wavelength of 1.0 x 10-3 nm.

GIVEN:

h x 10-34 J s

c = 3.00 x 108 m/s

= ?

= 1.0 x 10-3 nm = ???? m

WORK: = c = 3.00 108 m/s 1.0 x 10-12 m = 3.0 x 1020 s-1

E = hv c = λv

= (6.626 x 10-34 J s)(3.0 x 1020s-1)

E = 1.99 x 10-13 J

Equations with Wavelength and Equations with Wavelength and FrequencyFrequency

E = h

c = c = speed of light (2.998 x 108 m/s) = frequency (s-1)= wavelength (m)

E = energy (Joules or J)h= Planck’s constant (6.626 x10-34 J s) = frequency (s-1)

“nu” “lamda”

Highest energy

Moderate energy

Lowest energy

Common wavelength units for electromagnetic radiation

Picometer pm 10-12 Gamma ray

Ångstrom Å 10-10 X-ray

Nanometer nm 10-9 X-ray

Micrometer m 10-6 Infrared

Millimeter mm 10-3 Infrared

Centimeter cm 10-2 Microwave

Meter m 100 Radio

Unit Symbol Wavelength, (m) Type of Radiation

Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.

Bohr Model of Bohr Model of HydrogenHydrogen

Nucleus

Possible electron orbits

eGreat theory, BUT it turned out to be totally wrong!! Next week we’ll see a better theory

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 www.nisd.net/communicationsarts/pages/chem

Continuous and Line Spectra

light

Na

H

Ca

Hg

400 450 500 550 600 650 700 750 nm

Visiblespectrum

(nm)

Flame Test Emission Spectra

Photographs of flame tests of burning wooden splints soaked in different salts.Photographs of flame tests of burning wooden splints soaked in different salts.

methane gas wooden splint strontium ioncopper ionsodium ion calcium ion

Copyright © 2006 Pearson Benjamin Cummings. All rights reserved.

Example: Emission Spectrum of Hydrogen

410 nm 434 nm 486 nm 656 nm

ATOMIC SPECTRA: See p. 141 before Friday!

Other Elements Each element has a unique bright-line

emission spectrum.

i.e. “Atomic Fingerprint”

Helium

Bohr’s calculations only worked for hydrogen!

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e-e- Ground state

Excited state

Electrons can only be atspecific energy levels,NOT between levels.

Continuous vs. Quantized Continuous vs. Quantized EnergyEnergy

Ene

rgy

A Bcontinuous quantized

Acontinuous

Bquantized

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

1

23

456

Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

nucleus

Frequency A

Frequency B

Frequency C

n = 2

n = 1

n = 3

A

B

C

A + B = C

DO NOW: Draw this diagram in your notes and take out your HW from Mon & Tues.

DO NOW: Draw this diagram in your notes& take out HW

Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.