review of atomic and quantum theory pre einstein…. light exhibits wave characteristics -...

Review of Atomic and Quantum Theory

Pre Einstein….

Light exhibits Wave Characteristics - Electromagnetic Spectrum, Theory of “Ether”

Line Emission Spectrum, Photoelectric Effect - Light/Electrons show Particle Characteristics

WAVES PARTICLES

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

http://www.hetemeel.com/einsteinform.php

Bohr’s Model of the Atom





kosmoi.com/Science/ Physics/Quantum/

QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.

library.thinkquest.org

Bohr Model of Atom Electrons can only occupy specific “orbits”

Explains Line Emission Spectrums & Quantum Levels



Electrons show PARTICLE characteristics

http://kosmoi.com/Science/Physics/Quantum/



The Swinging Pendulum…



www.blazelabs.com/ f-p-prop.asp

DeBroglie - Explained “particle” nature of Line Emissions with mathematical equations for WAVES.



http://dbhs.wvusd.k12.ca.us/webdocs/Gallery/Gallery5.html


Light/Electrons show WAVE properties

Light/Electrons show PARTICLE properties

Remember the Interference Patterns of Waves at Station 4?

www.sr.bham.ac.uk/ xmm/diffpage1.html




This is a photograph of an a beam of electrons passed through a substance.

This is a picture of light being “confined” in a telescope.

DeBroglie: A “confined wave”, acts similarly to particles.

http://dbhs.wvusd.k12.ca.us/webdocs/Gallery/Gallery15.html

So Where Are They? The Heisenberg Uncertainty Principle

•Electrons are particles that can be described in terms of BOTH waves and PARTICLES.•If you know where the electron is, then you can’t determine its speed or direction.





OBSERVATION changes the behavior of the electron

If you know the electrons speed and direction, you don’t know where the electron is.

Schrodinger


www.malaspina.org



digg.com/general_sciences/ e=mc%C2%B2_explained

Schrodinger developed complex mathematical equations using “quantum numbers “ to describe what Bohr observed but his equations described WAVES not particles.

http://digg.com/general_sciences/e=mc%C2%B2_explained

http://digg.com/general_sciences/e=mc%C2%B2_explained



boomeria.org/chemlectures/orbitals/orbitals.html



Wait a minute… I don’t buy this! “God does not throw dice!

http://www.biografiasyvidas.com/monografia/einstein/fotos/einstein_1947.jpg



http://boomeria.org/chemlectures/orbitals/orbitals.html

When Schrodinger put his “quantum numbers” in his equations, mathematically he could calculate the energy levels that Bohr explained with his “planetary” model of the atom.

Quantum Energy Levels



Energy Levels

Quantum Number “n”Quantum “shapes” (sublevel) (Quantum Number “l”)

Orbitals



http://boomeria.org/chemlectures/orbitals/shapeclouds.jpg

Electron Orbitals Example



http://fig.cox.miami.edu/~cmallery/150/chemistry/c2x11orbitals.jpg

D Orbitals



http://www4.nau.edu/microanalysis/Microprobe/img/orbital.jpg

1 Dimensional View of Orbitals



www.answers.com/ topic/quantum-mechan

http://www.answers.com/topic/quantum-mechanics

http://www.answers.com/topic/quantum-mechanics

Actual Electron Cloud



Image of the electron cloud around a nickle impurity in a high-temperature superconductor, obtained with a scanning tunneling microscope. The central spot is the nickle atom, surrounded by a cloverleaf pattern whose fourfold symmetry is indicative of the underlying d-wave nature of the high-temperature superconducting state.PHOTO CREDIT: Seamus Davis/UC Berkeley

http://www.berkeley.edu/news/media/releases/2001/06/20_physc.html

Electron Configurations

Definition - The arrangement of the electrons in an atom.

• unique to each atom

• tend to assume arrangements that have the lowest possible energy levels

“Ground State Configuration” Defenition -

Lowest Energy State arrangement



http://hi.fi.tripod.com/timeline/images/electron_cloud.jpg

Rules for Defining Electon Configurations

• Aufbau Principle - an electron occupies the lowest-energy orbital

•Pauli Exclusion Principle - No two electrons in the same atom can have the same set of 4 quantum numbers.

•Hunds Rule - orbitals of equal energy have one electron before a second electron is added, and spin direction is the same for single electrons in that energy level.



How are Electron Configurations Written

•Energy Level Comes First…

•Shape Comes Second…

•Number of Electrons in the shape comes Third as a superscript…

•Spin is “implied by # of electrons

“1”, “2”, etc.

“1s”, “2s”, “2p”, etc.

“1s1”, “1s2”, “2s1” , etc.



http://www.beyondbooks.com/psc92/images/00080041.jpg

Practical Application



Start with Hydrogen…

• Hydrogen has one electron.

•Lowest Energy Level is “1”

•Lowest Energy Shape is “spherical”

Lowest Energry Level

So… electron configuration will be “1s”

Practical Application - Helium



Helium has 2 electrons



•Two electrons will occupy orbital with different “spins”

Lowest Energry Level

So… electron configuration will be “1s2”

Electron Configuration Handout

Write the Electron Configuration for

Hydrogen:

Helium:

1s

2s 2p3s

3p

3d4s

1s

1s2

Practical Application - Lithium



Lithium has 3 electrons



•Two electrons will occupy orbital with different “spins”

•Next lowest Energy State is level “2”

•The Lowest Energy Shape at level “2” is spherical

So… electron configuration will be “1s22s”

Lowest Energy State

Second Lowest Energy

State

Noble Gas Nomenclature

•When you get to a “Noble Gas”, the electrons fill up all the orbitals on that energy level.

•You can now describe those electrons with the designation of the Noble Gas in “[brackets]”

•Example…Lithium can be described as 1s22s or [He]2s since it has all the electrons for Helium plus one more.



Practical Application - Beryllium



Beryllium has 4 electrons…

•Beryllium fills up all of the orbitals for “Lithium” then…

•Adds an additional electron to the same spherical shape as the one Lithium used last

So… electron configuration will be “1s22s2”

Lowest Energy State


State

Practical Application - Boron



Boron has 5 electrons…

•Boron fills up all of the orbitals for “Beryllium” then…

•Uses a new shape, but same energy level. The “p” “shape” can hold up to 6 electrons because of the 3 dimensional orientation.

•Remember, to NEXT put electrons in each 3 dimensional section of the orbital before putting two together. What rule would this relate to?So… electron configuration will be “1s22s22p”

Lowest Energy State


State

Same Energy

Level, different

shape


1s

2s 2p3s

3p

3d4s

Practical Application - Carbon, Nitrogen, Oxygen, Flourine, Neon



Carbon has 6 electrons

So… electron configuration will be “1s22s22p2”

•Nitrogen has 7 electronsSo… electron configuration will be “1s22s22p3”

What are the electron configurations for Oxygen, Flourine and Neon?

Lowest Energy State


State

Same Energy

Level, different

shape


1s

2s 2p3s

3p

3d4s

Now we are at Argon… What next?

Notice that the next lowest energy level is not “3d” but “4s”!

Sometimes different shapes have different energy levels than are “lower” than the Quantum number level.

So the electron configuration added for Potassium starts at “4s”

review of atomic and quantum theory pre einstein…. light exhibits wave characteristics -...

Documents

topicquantummechan slide

electron orbitals example

quantum numbers

d orbitals http

bohr model of atom electrons

atom kosmoi

nickle atom

electrons speed