1. Warmup Use the periodic table and the diagram below to write and sketch (when possible) the orbitals for: Na P Ag

2. Warmup Solutions Na 1s 2 2s 2 p 6 3s 1 P Ag

3. Warmup 2 Wave Equation 1)An ocean wave has a velocity of 15 m/s and a wavelength of 30 m. What is the frequency in Hz? 2)A light wave has a wavelength of 660 nm. What is its frequency? Planck’s Equation 3) h  Planck’s Constant (6.63 * 10 -34 J*s) f  frequency (Hz) use answer from problem 2. What is the energy of this photon?

4. SEPTEMBER 20 TH 2010 Bohr Model: Quantized Orbits Rydberg Formula Emission Spectra Flame Test

5. Bohr Model: Quantized Orbits Main Principles: Atoms have discrete electron orbital patterns. Higher orbits hold more potential energy. A fall from a higher orbital to a lower one releases energy as light. (Energy is conserved) http://www.physchem.co.za/OB12-mat/spectra.htm Visible Ultraviolet Infrared

6. Relevant Equations Potential Energy PE = F * dPE  Potential Energy (J) F  Force of attraction (N) d  Distance (m) Waves v = λ * fv  velocity (3*10 8 m/s) λ  wavelength (m) f  frequency (Hz) Quantization of Photons E = h * fE  Energy (J) h  Planck’s Constant (6.63 * 10 -34 J*s) f  frequency (Hz) Rydberg Formula 1/ λ = R Z 2 (n 1 -2 – n 2 -2 )λ  wavelength (m) R  Rydberg’s Constant (1.1*10 -7 m -1 ) Z  Atomic number n  electron orbital number

7. Flame Test Goals: 1) Measure the emission spectrum of a particular element. 2) Calculate the frequency and energy of the photons emitted. 3) Compare the measured wavelength to the Rydberg Formula prediction, and identify the line. Assumptions: 1) All visible lines are in the Balmer series (n=2). (Probably true) 2) Each element is ionized down to a single valence electron. (?!) Materials: Metal salts or nitrates Wire or heat-resistant ladles Propane torches Diffraction grating spectroscopes Backup: Spectroscopy tubes Resources: http://webmineral.com/help/FlameTest.shtml

8. Data Table Sample ElementMeasured λ (nm) Predicted λ (nm) Upper “n” number Frequency (Hz) Energy (J)