Presentation on theme: "Wavelength, Frequency, & Energy of Light"— Presentation transcript:
1 Wavelength, Frequency, & Energy of Light Byno Chemistry 2013
2 Discuss in your group Why does Aluminum not burn? Why does Alcohol burn but it will not react with anything else?Why does Aluminum react with Hydrochloric Acid?Why does Calcium Carbonate react with vinegar, but it doesn’t burn?
3 I can . . .Identify and use the symbols for frequency and speed of lightUse 3x108 m/s as the value for the speed of lightCalculate E = hv using Planck’s constantCalculate c = λv using the speed of light
4 Symbols Symbol Meaning Value or Unit c Speed of light 3x108 m/s h Planck’s constant6.63 x JsEEnergyJoules (J)νfrequencyHertz (Hz)λwavelengthNanometer (nm)
5 Visible LightVisible light breaks into a spectrum of colors depending on the wavelength of the light
6 SpectroscopeA spectroscope is a device used to separate the colors of visible light and measure their wavelengths
7 Electron Energy Levels Electrons exist in the electron cloud but they can be found in distinct ‘levels’They are the s-orbital, p-orbital, d-orbital, and f-orbitalElectrons can jump up from one orbital to the next when energy is applied to the atom
12 F-orbitalLanthinide and Actinide series – Rare Earth Metals
13 ElectronsThe motion of electrons in the electron cloud of an atom creates low energy waves such as visible light and radio wavesThe energy is the result of electrons hopping from one level up to the nextEnergy is emitted when the electron falls back to the original level
14 ReactivityAn element can react with another element if it has electrons that can moveWhen a chemical substance reacts with another, the electrons move and give off energy in the form of light
15 WavelengthThe energy of the electron’s movement in a chemical reaction can be calculatedSpeed of light (m/s)Wavelength(m)Frequency (Hz)Example: A helium laser emits light with a wavelength of 633 nm. What is the frequency of the light?
16 EnergyNow that we know the wavelength, we can calculate the energy of the electronEnergy(J)Frequency(Hz)h (Planck’s Constant)6.63 x JsExample: A helium laser emits light with a wavelength of 633 nm. What is the energy of its electrons?We previously calculated frequency = 6.00 Hz
17 PracticeWhat is the energy of light whose wavelength is 4.06 x m?c÷λ = νν = 3.8x108 m/s ÷ 4.06x10-11 mν = 7.39x1018 HzE = h × νE = 6.63x10-34 Js × 7.39x1018 HzE = 4.9x10-15 J