ELECTROMAGNETIC SPECTRUM refer to your handouts and pages 731 to 737 label the following: 7 types of electromagnetic waves largest and smallest frequency largest and smallest wavelength largest and smallest energy largest and smallest temperature 1-2 major characteristics of each wave examples/uses of each wave answer the following questions: what is an electromagnetic wave? summarize bottom of page 734 does an EM wave require a medium? what is the SI unit for frequency? what is the SI unit for wavelength? what is the SI unit for energy? what is the SI unit for temperature? what equation relates wavelength to frequency?

radio (smallest frequency, largest wavelength, smallest energy level, smallest temperature) travel easily around objects to transmit information across long distances radios and televisions microwave emitted by all matter at typical temperatures, penetrate through non-dense objects heat food, Doppler radar for weather, study stars, satellite communication infrared heat given off by anything warm (sun, fire, human bodies) remote controls, burglar alarms, night-vision goggles visible emitted by the sun and other hot objects, only waves visible to humans light bulbs ultraviolet emitted by the sun and other hot objects, causes sunburn disinfectant to kill bacteria in city water supplies or to sterilize equipment in hospitals x-rays emitted by very high energy sources (supernovas and radioactive material), can travel through solid objects x-ray machines gamma (largest frequency, smallest wavelength, largest energy level, largest temperature) emitted by extremely high energy sources (nuclear explosions and destruction of atoms), harmful to humans kill cancerous cells

what is an electromagnetic wave? a wave of perpendicularly oscillating electric and magnetic fields which radiate outward from the source at the speed of light what is a photon? a quantum of light, has energy but not mass does an EM wave require a medium? no what is the SI unit for frequency? hertz (Hz) what is the SI unit for wavelength? meter (m) what is the SI unit for energy? electron volt (eV) what is the SI unit for temperature? kelvin (K) what equation relates wavelength to frequency? λ = c/f λ = wavelength c = the speed of light = 3.00 x 108 m/s f = frequency

The Photoelectric Effect Energy-Level Diagrams PROBLEM SET due Monday the 26th 25 pts (completion) Quantum Energy Page 755 Practice A #1-4 The Photoelectric Effect Page 758 Practice B #1&4 Energy-Level Diagrams Page 769 Practice C #2&3 DeBroglie Waves Page 774 Practice D #1,4,5

refer to your handouts and pages 752 to 755 BLACKBODY RADIATION refer to your handouts and pages 752 to 755 blackbody – a perfect radiator and absorber and emits radiation based only on its temperature

refer to your handouts and pages 756 to 760 PHOTOELECTRIC EFFECT refer to your handouts and pages 756 to 760 photoelectric effect – the emission of electrons from a material surface that occurs when light of certain frequencies shines on the surface of the material

MODELS OF THE ATOM Create a timeline of three models of the atom. refer to your handouts and pages 762 to 763 Create a timeline of three models of the atom. Include the following: name of scientist short description of model picture of model

refer to your handouts and pages 763 to 765 ATOMIC SPECTRA refer to your handouts and pages 763 to 765 atomic spectra – an empty glass tube is filled with a pure atomic gas, then a high potential difference is applied between metal electrodes to produce a current in the gas, then the tube gives off light that is characteristic of the gas uses: emission lines can identify elements in a mixture and absorption lines can identify elements in the solar system

BOHR MODEL OF HYDROGEN ATOM refer to your handouts and pages 765 to 770 problems with this model: ~ only valid for atoms containing one electron ~ violated the laws of classical physics because electrons in a circular orbit would accelerate to the center, not maintain a fixed circular orbit ~ violated Heisenberg’s uncertainty principal because electrons were considered to have both a known radius (position) and orbit (momentum) ~ no explanation for the assumption that electrons do not radiate energy when in a stable orbit ~ no explanation for why electrons have certain stable orbits

refer to your handouts and pages 771 to 772 DUAL NATURE OF LIGHT refer to your handouts and pages 771 to 772

refer to your handouts and pages 772 to 774 MATTER WAVES refer to your handouts and pages 772 to 774 matter waves – also called deBroglie waves; reflects the wave-particle duality of matter; wavelength is indirectly proportional to momentum (λ = h/p) and frequency is directly proportional to energy (f = E/h)

UNCERTAINTY PRINCIPLE refer to your handouts and pages 775 to 776 uncertainty principle – it is impossible to simultaneously determine a particle’s position and momentum with infinite accuracy

refer to your handouts and pages 776 to 777 ELECTRON CLOUD refer to your handouts and pages 776 to 777 electron cloud – the region of negative charge surrounding an atomic nucleus that is associated with an orbital; idea was first proposed by Schrodinger

Timeline of Quantum Physics