1. Waves All waves, whether they are water waves or electromagnetic waves, can be described in terms of four characteristics: amplitude wavelength frequency speed

2. Amplitude The amplitude of a wave is the height of the wave measured from the origin to its crest. The amplitude of a wave is the height of the wave measured from the origin to its crest. www.hyperphysics.phys-astr.gsu.edu

3. Wavelength The wavelength of a wave is the distance that the wave travels as it completes one full cycle of upward and downward motion. The wavelength of a wave is the distance that the wave travels as it completes one full cycle of upward and downward motion. www.hyperphysics.phys-astr.gsu.edu http://www.800mainstreet.com/spect/emission-flame-exp.html

4. Visible Light Wavelengths Visible light has wavelengths in the range of 400 to 750 nm Visible light has wavelengths in the range of 400 to 750 nm Remember that a nanometer is 10 -9 meter Remember that a nanometer is 10 -9 meter You may remember the visible light spectrum as ROYGBIV You may remember the visible light spectrum as ROYGBIV

5. Frequency The frequency of a wave tells how fast the wave oscillates up and down. The frequency of a wave tells how fast the wave oscillates up and down. The frequency of light is measured by the number of times a light wave completes a cycle of upward and downward motion in one second. The frequency of light is measured by the number of times a light wave completes a cycle of upward and downward motion in one second. Units can be: cycles/sec or Hertz Units can be: cycles/sec or Hertz

6. Speed of Light Light moves through space at a constant speed of 3.00 x 10 8 m/s Light moves through space at a constant speed of 3.00 x 10 8 m/s You will use c = 3.00 x 10 8 m/s You will use c = 3.00 x 10 8 m/s

7. Wavelength and Frequency Calculation λ = c/v λ = c/v If the frequency of radiation is 3 x 10 15 cycles/sec, what is the wavelength? If the frequency of radiation is 3 x 10 15 cycles/sec, what is the wavelength?

8. Wavelength and Frequency Calculation λ = c/v λ = c/v If the wavelength of radiation is If the wavelength of radiation is 3 x 10 -4 m, what is the frequency?

9. Electromagnetic Spectrum Electromagnetic radiation can be described in terms of a stream of photons, which are massless particles each traveling in a wave-like pattern and moving at the speed of light. Each photon contains a certain amount (or bundle) of energy, and all electromagnetic radiation consists of these photons. The only difference between the various types of electromagnetic radiation is the amount of energy found in the photons. Radio waves have photons with low energies, microwaves have a little more energy than radio waves, infrared has still more, then visible, ultraviolet, X-rays, and... the most energetic of all... gamma-rays. Electromagnetic radiation can be described in terms of a stream of photons, which are massless particles each traveling in a wave-like pattern and moving at the speed of light. Each photon contains a certain amount (or bundle) of energy, and all electromagnetic radiation consists of these photons. The only difference between the various types of electromagnetic radiation is the amount of energy found in the photons. Radio waves have photons with low energies, microwaves have a little more energy than radio waves, infrared has still more, then visible, ultraviolet, X-rays, and... the most energetic of all... gamma-rays.photonsspeed of lightphotonsspeed of light

10. Electromagnetic Spectrum http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html

11. Radio Waves RadioRadio: yes, this is the same kind of energy that radio stations emit into the air for your boom box to capture and turn into your favorite Mozart, Madonna, or Coolio tunes. But radio waves are also emitted by other things... such as stars and gases in space. You may not be able to dance to what these objects emit, but you can use it to learn what they are made of. stars Radiostarshttp://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html

12. Radio Waves http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html

13. Microwaves Microwaves: they will cook your popcorn in just a few minutes! In space, microwaves are used by astronomers to learn about the structure of nearby galaxies, including our own Milky Way! Microwaves: they will cook your popcorn in just a few minutes! In space, microwaves are used by astronomers to learn about the structure of nearby galaxies, including our own Milky Way! Microwaves astronomers Microwaves astronomers http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html

14. Infrared Radiation Infrared: we often think of this as being the same thing as 'heat', because it makes our skin feel warm. In space, IR light maps the dust between stars. Infrared: we often think of this as being the same thing as 'heat', because it makes our skin feel warm. In space, IR light maps the dust between stars.dust http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html

15. Visible Light Visible: yes, this is the part that our eyes see. Visible radiation is emitted by everything from fireflies to light bulbs to stars... also by fast-moving particles hitting other particles. Visible: yes, this is the part that our eyes see. Visible radiation is emitted by everything from fireflies to light bulbs to stars... also by fast-moving particles hitting other particles. Visible

16. Don’t All Units Work The Same? In the older "CGS" version of the metric system, the units used were angstroms. An Angstrom is equal to 0.0000000001 meters (10-10 m in scientific notation)! In the newer "SI" version of the metric system, we think of visible light in units of nanometers or 0.000000001 meters (10-9 m). In this system, the violet, blue, green, yellow, orange, and red light we know so well has wavelengths between 400 and 700 nanometers. In the older "CGS" version of the metric system, the units used were angstroms. An Angstrom is equal to 0.0000000001 meters (10-10 m in scientific notation)! In the newer "SI" version of the metric system, we think of visible light in units of nanometers or 0.000000001 meters (10-9 m). In this system, the violet, blue, green, yellow, orange, and red light we know so well has wavelengths between 400 and 700 nanometers.metricangstromsscientific notationSImetricangstromsscientific notationSI http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html

17. Visible Spectrum http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html http:// www.800mainstreet.com/spect/emission-flame-exp.html

18. Ultraviolet Radiation Ultraviolet: we know that the Sun is a source of ultraviolet (or UV) radiation, because it is the UV rays that cause our skin to burn! Stars and other "hot" objects in space emit UV radiation. Ultraviolet: we know that the Sun is a source of ultraviolet (or UV) radiation, because it is the UV rays that cause our skin to burn! Stars and other "hot" objects in space emit UV radiation. Ultraviolet http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html

19. X-ray Radiation X-rays: your doctor uses them to look at your bones and your dentist to look at your teeth. Hot gases in the Universe also emit X-rays. X-rays: your doctor uses them to look at your bones and your dentist to look at your teeth. Hot gases in the Universe also emit X-rays. X-rays Universe X-rays Universe http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html

20. Gamma Radiation Gamma-rays: radioactive materials (some natural and others made by man in things like nuclear power plants) can emit gamma- rays. Big particle accelerators that scientists use to help them understand what matter is made of can sometimes generate gamma- rays. But the biggest gamma-ray generator of all is the Universe! It makes gamma radiation in all kinds of ways. Gamma-rays: radioactive materials (some natural and others made by man in things like nuclear power plants) can emit gamma- rays. Big particle accelerators that scientists use to help them understand what matter is made of can sometimes generate gamma- rays. But the biggest gamma-ray generator of all is the Universe! It makes gamma radiation in all kinds of ways. Gamma-raysmatter Gamma-raysmatter

21. Gamma Radiation http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html

22. Which types of radiation reach the Earth? http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html

23. What is Electromagnetic Radiation? Electromagnetic radiation from space is unable to reach the surface of the Earth except at a very few wavelengths, such as the visible spectrum, radio frequencies, and some ultraviolet wavelengths. Astronomers can get above enough of the Earth's atmosphere to observe at some infrared wavelengths from mountain tops or by flying their telescopes in an aircraft. Experiments can also be taken up to altitudes as high as 35 km by balloons which can operate for months. Rocket flights can take instruments all the way above the Earth's atmosphere for just a few minutes before they fall back to Earth, but a great many important first results in astronomy and astrophysics came from just those few minutes of observations. For long-term observations, however, it is best to have your detector on an orbiting satellite... and get above it all! Electromagnetic radiation from space is unable to reach the surface of the Earth except at a very few wavelengths, such as the visible spectrum, radio frequencies, and some ultraviolet wavelengths. Astronomers can get above enough of the Earth's atmosphere to observe at some infrared wavelengths from mountain tops or by flying their telescopes in an aircraft. Experiments can also be taken up to altitudes as high as 35 km by balloons which can operate for months. Rocket flights can take instruments all the way above the Earth's atmosphere for just a few minutes before they fall back to Earth, but a great many important first results in astronomy and astrophysics came from just those few minutes of observations. For long-term observations, however, it is best to have your detector on an orbiting satellite... and get above it all! Electromagnetic radiationwavelengthsvisible spectrumradio frequenciesatmosphereinfraredastronomy astrophysicsorbitingsatellite Electromagnetic radiationwavelengthsvisible spectrumradio frequenciesatmosphereinfraredastronomy astrophysicsorbitingsatellitehttp://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html

24. Planck’s Theory Max Planck proposed that there is a fundamental restriction on the amounts of energy that an object emits or absorbs, and he called each of these pieces of energy a quanta. Max Planck proposed that there is a fundamental restriction on the amounts of energy that an object emits or absorbs, and he called each of these pieces of energy a quanta. E = hv E = hv Planck’s constant is Planck’s constant is h= 6.626 x 10 -34 Js

25. Planck’s Equation E = hv E = hv E = amount of energy emitted or absorbed E = amount of energy emitted or absorbed h = Planck’s constant 6.626x10 -34 Js h = Planck’s constant 6.626x10 -34 Js

26. Photoelectric Effect Einstein used Planck’s equation E=hv to explain the photoelectric effect. Einstein used Planck’s equation E=hv to explain the photoelectric effect. In the photoelectric effect, electrons are ejected from the surface of a metal when light shines on the metal In the photoelectric effect, electrons are ejected from the surface of a metal when light shines on the metal Einstein proposed that light consists of quanta of energy that behave like tiny particles of light. Einstein proposed that light consists of quanta of energy that behave like tiny particles of light. Energy quanta are photons. Energy quanta are photons.

27. Arthur Compton Compton demonstrated that a photon could collide with an electron, therefore a photon behaves like a particle. Compton demonstrated that a photon could collide with an electron, therefore a photon behaves like a particle.

28. DeBroglie Louis de Broglie determined that particles exhibit wavelike behavior. Louis de Broglie determined that particles exhibit wavelike behavior.

29. Dual Nature of Light Light acts like particle and behaves like a wave. Light acts like particle and behaves like a wave.

30. Types of Spectra Continuous Spectrum – a blend of colors one into the other. Continuous Spectrum – a blend of colors one into the other. An example of a continuous spectrum is a rainbow. An example of a continuous spectrum is a rainbow.

31. Types of Spectra Emission Spectrum (Bright-line spectrum) Emission Spectrum (Bright-line spectrum) - a spectrum that contains only certain colors, or wavelengths Energy is added to an element sample. The electrons absorb the energy and jump to a higher energy level. They only stay there for an instant and then fall back to a lower energy level. As the electrons fall back down they emit photons of light. Each photon has a specific wavelength and frequency. Energy is added to an element sample. The electrons absorb the energy and jump to a higher energy level. They only stay there for an instant and then fall back to a lower energy level. As the electrons fall back down they emit photons of light. Each photon has a specific wavelength and frequency.

32. www.cms.k12.nc.us/.../notes/ch04electrons.html www.cms.k12.nc.us/.../notes/ch04electrons.html www.cms.k12.nc.us/.../notes/ch04electrons.html

33. http://www.800mainstreet.com/spect/emission-flame-exp.html http://www.800mainstreet.com/spect/emission-flame-exp.html

34. Creating Emission Spectrum Lines http://www.800mainstreet.com/spect/emission-flame-exp.html http://www.800mainstreet.com/spect/emission-flame-exp.html

35. Helium Spectrum http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/atspect.html

36. Colorful Chemicals Try this web site to see the colorful spectra that different metals can create. Try this web site to see the colorful spectra that different metals can create. http://webmineral.com/help/FlameTest.shtml http://webmineral.com/help/FlameTest.shtml

37. Bohr’s Model of the Atom Bohr listened to a lecture by Rutherford (about his model of the atom). He realized how Planck’s idea of quantization could be applied to this model to explain line spectra. Bohr listened to a lecture by Rutherford (about his model of the atom). He realized how Planck’s idea of quantization could be applied to this model to explain line spectra. He decided that electrons can be found only in specific energy levels with specific amounts of energy. He decided that electrons can be found only in specific energy levels with specific amounts of energy. Each energy level was assigned a quantum number Each energy level was assigned a quantum number The ground state is the lowest energy level, n=1, this energy level is closest to the nucleus The ground state is the lowest energy level, n=1, this energy level is closest to the nucleus Electrons absorb a specific quanta of energy and jump to an excited state, n=2 or above Electrons absorb a specific quanta of energy and jump to an excited state, n=2 or above

38. Bohr’s Explanation of Hydrogen’s Spectral Lines Bohr proposed that when radiation is absorbed, an electron jumps from the ground state to an excited state. Radiation is emitted when the electron falls back from the higher energy level to a lower one. The energy of the absorbed or emitted radiation equals the difference between the two energy levels involved. Bohr proposed that when radiation is absorbed, an electron jumps from the ground state to an excited state. Radiation is emitted when the electron falls back from the higher energy level to a lower one. The energy of the absorbed or emitted radiation equals the difference between the two energy levels involved.

39. Bohr’s Explanation of Hydrogen’s Spectral Lines Continued Bohr used his model and Planck’s equation, E=hv, to calculate the frequencies observed in the line spectrum of hydrogen. Bohr used his model and Planck’s equation, E=hv, to calculate the frequencies observed in the line spectrum of hydrogen. This model worked well for hydrogen with one electron, but not for elements with larger numbers of electrons. This model worked well for hydrogen with one electron, but not for elements with larger numbers of electrons.

40. Planck, Einstein and Bohr described light as consisting of photons – quanta of energy that have some of the characteristics of particles. Planck, Einstein and Bohr described light as consisting of photons – quanta of energy that have some of the characteristics of particles.

41. Heisenberg’s Uncertainty Principle Heisenberg stated that the position and the momentum of a moving object cannot simultaneously be measured and known exactly. Heisenberg stated that the position and the momentum of a moving object cannot simultaneously be measured and known exactly.

42. Probability of Locating an Electron in an Atom think of the electrons as residing in a cloud think of the electrons as residing in a cloud more dense areas have a higher probability of finding an electron more dense areas have a higher probability of finding an electron Draw a diagram of an atom with a surrounding electron cloud Draw a diagram of an atom with a surrounding electron cloud

43. Quantum Mechanical Model of the Atom

44. Atomic Orbitals An atomic orbital is a region around the nucleus of an atom where an electron with a given energy is likely to be found. An atomic orbital is a region around the nucleus of an atom where an electron with a given energy is likely to be found. The amount of energy an electron has determines the kind of orbital it occupies. The amount of energy an electron has determines the kind of orbital it occupies.

45. s sublevel s orbitals are spherical in shape s orbitals are spherical in shape http://www.chemsoc.org/exemplarchem/entries/2004/dublin_fowler/sorbitals.html

46. p sublevels p orbitals are dumbbell shaped p orbitals are dumbbell shaped P x P y P z P x P y P z http://www.chemsoc.org/exemplarchem/entries/2004/dublin_fowler/sorbitals.html http://www.chemsoc.org/exemplarchem/entries/2004/dublin_fowler/sorbitals.html

47. d sublevels d orbitals can be several shapes d orbitals can be several shapes d z2 d x2-y2 d xy http://www.chemsoc.org/exemplarchem/entries/2004/dublin_fowler/sorbitals.html http://www.chemsoc.org/exemplarchem/entries/2004/dublin_fowler/sorbitals.html

48. d sublevels d xz d yz d xz d yz http://www.chemsoc.org/exemplarchem/entries/2004/dublin_fowler/sorbitals.html http://www.chemsoc.org/exemplarchem/entries/2004/dublin_fowler/sorbitals.html

49. f sublevels f orbitals are complicated 3D shapes that need to be computer generated f orbitals are complicated 3D shapes that need to be computer generated see http://nobel.scas.bcit.ca/chem0010/un it3/3.3.3_QM_econfig.htm#here see http://nobel.scas.bcit.ca/chem0010/un it3/3.3.3_QM_econfig.htm#here

50. “To Do” Activity Color the s, p, d, f blocks on the periodic table. Color the s, p, d, f blocks on the periodic table.

51. Principal Energy Levels Principal energy levels in an atom are designated by the quantum number, n. Principal energy levels in an atom are designated by the quantum number, n. “n” must be an integer “n” must be an integer look at the left hand margin of the periodic table to find the principal quantum numbers look at the left hand margin of the periodic table to find the principal quantum numbers As “n” increases (i.e. from 1 to 2), the electron energy increases As “n” increases (i.e. from 1 to 2), the electron energy increases

52. Sublevels Each principal energy level is divided into one or more sublevels. Each principal energy level is divided into one or more sublevels. The number of sublevels in each principal energy level equals the quantum number, n, for that energy level. The number of sublevels in each principal energy level equals the quantum number, n, for that energy level.

53. How do you tell the difference between sublevels? Sublevels can be distinguished by their: Sublevels can be distinguished by their: –shapes –sizes –energies

54. Sublevels If “n” = 1one sublevel“s” If “n” = 1one sublevel“s” If “n” = 22 sublevels “s” and “p” If “n” = 22 sublevels “s” and “p” If “n” = 33 sublevels “s”, “p”, “d” If “n” = 33 sublevels “s”, “p”, “d”

55. Orbitals Each sublevel consists of one or more orbitals. Each sublevel consists of one or more orbitals. There can never be more than 2 electrons in each orbital. There can never be more than 2 electrons in each orbital.

56. Electrons in Orbitals Electrons behave as if they are spinning on their own axis. Electrons behave as if they are spinning on their own axis. A spinning charge creates an electric and magnetic field. A spinning charge creates an electric and magnetic field.

57. Pauli’s Exclusion Principle 1.Each orbital in an atom can hold at most 2 electrons 1.Each orbital in an atom can hold at most 2 electrons 2.Each of these electrons must have opposite spins. 2.Each of these electrons must have opposite spins.

58. Electron Pairing Two electrons with opposite spins (in the same orbital) are paired. Two electrons with opposite spins (in the same orbital) are paired. Sublevel “s” holds 2 e Sublevel “s” holds 2 e Sublevel “p” holds 6 e Sublevel “p” holds 6 e Sublevel “d” holds 10 e Sublevel “d” holds 10 e Sublevel “f” holds 14 e Sublevel “f” holds 14 e

59. Orbital Diagram “To Do” Activity Acquire a clean orbital diagram. Acquire a clean orbital diagram. Only use pencil on your diagram. Only use pencil on your diagram. Use an orbital to build an electron configuration. Use an orbital to build an electron configuration.

60. Aufbau Principle Electrons are added one at a time to the lowest energy orbitals available until all of the electrons of the atom have been accounted for. Electrons are added one at a time to the lowest energy orbitals available until all of the electrons of the atom have been accounted for.

61. Pauli Exclusion Principle An orbital can hold up to 2 electrons An orbital can hold up to 2 electrons Electrons in the same orbital must have opposite spins Electrons in the same orbital must have opposite spins

62. Hund’s Rule Electrons occupy equal energy orbitals so that a maximum number of unpaired electrons results. Electrons occupy equal energy orbitals so that a maximum number of unpaired electrons results. This is commonly known as the “Seat on the Bus” Rule This is commonly known as the “Seat on the Bus” Rule