Electronic structure: arrangement of electrons in atomsRefers to the number of electrons in the atom as well as their distribution around the nucleus and their energiesHelps us to understand the arrangement of the elements in the periodic tableQuantum theory – used to explain behavior of electrons in atomsQuantum physics – physics used to describe electronsLight we see with our eyes  visible lightElectromagnetic radiation – carries energy through space (radiant energy)All move through a vacuum at 3.00 X 10^8 m/s (speed of light)All have wavelike characteristics (expressed as up and down movements)Wavelength – distance between two adjacent peaks or troughsFrequence – wavelengths (or cycles) that pass a given point each secondC=λνc is speed of lightλ is wavelengthν is frequencyelectromagnetic spectrum – shows various types of electromagnetic radiation arranged in order of increasing wavelengthFrequency is expressed in cycles per second or hertz (Hz)(s^(-1) or 1/s)Sample Exercise 6.1A) the upper wave has higher frequency because it has shorter wavelength.B) the upper wave would be visible light and the lower wave would be infrared radiationSample Exercise 6.2The yellow light given off by a sodium vapor lamp used for public lighting has a wavelength of 589 nm. What is the frequency of this radiation?C=λvv = c/λ =3 phenomena are not explainedblackbody radiation – emission of light from hot objectsphotoelectric effect – emission of electrons from metal surfaces on which light shinesemission spectra – emission of light from electronically excited gas atomsWhen solids are heated they emit radiation (red glow on electric stove)Wavelength distribution of radiation depends on temperatureQuantum  means fixed amountSmallest quantity of energy that can be emitted or absorbed as electromagnetic radiationE=hvh = planck’s constant  6.626 X 10^-34 J-sphoton – packet of energywork function = amount of energy require for the electrons to overcome the attractive forces holding them in the metalspectrum : dispersion of radiation into its component wavelengthscontinuous spectrum: if spectrum contains all wavelengthsline spectrum : contains only specific wavelengthsBohr’s model postulates:only orbits of certain radii, corresponding to certain specific energies, are permitted for the electron in a hydrogen atoman electron in a permitted orbit is in a “allowed” energy state. An electron in an allowed energy state does not radiate energy and, therefore, does not spiral into the nucleusenergy is emitted or absorbed by the electron only as the electron changes from one allowed energy state to another. This energy is emitted or absorbed as a photon that has energy E=hvground state  lowest energy stateexcited state  electron is in higher energy stateelectron must absorb energy to move to higher-energy statewavelength and frequency are always reported as positive quantities.Negative is used to express direction of energy flowBohr’s model explained the hydrogen atom but not other spectra2 ideas still included in current model:electrons exist only in certain discrete energy levels, which are described by quantum numbersenergy is involved in the transition of an electron from one level to anothermomentum – mv (mass • velocity)matter waves- wave characteristics of material particlesReading Notes 09/25/2012Electronic structure: arrangement of electrons in atomsRefers to the number of electrons in the atom as well as their distribution around the nucleus and their energiesHelps us to understand the arrangement of the elements in the periodic tableQuantum theory – used to explain behavior of electrons in atomsQuantum physics – physics used to describe electronsLight we see with our eyes  visible lightElectromagnetic radiation – carries energy through space (radiant energy)All move through a vacuum at 3.00 X 10^8 m/s (speed of light)All have wavelike characteristics (expressed as up and down movements)Wavelength – distance between two adjacent peaks or troughsFrequence – wavelengths (or cycles) that pass a given point each second C=λν-c is speed of light -λ is wavelength-ν is frequencyelectromagnetic spectrum – shows various types of electromagnetic radiation arranged in order of increasing wavelengthFrequency is expressed in cycles per second or hertz (Hz) (s^(-1) or 1/s)Sample Exercise 6.1A) the upper wave has higher frequency because it has shorter wavelength.B) the upper wave would be visible light and the lower wave would be infrared radiationSample Exercise 6.2The yellow light given off by a sodium vapor lamp used for public lighting has a wavelength of 589 nm. What is the frequency of this radiation?C=λvv = c/λ = 3 phenomena are not explained-blackbody radiation – emission of light from hot objects-photoelectric effect – emission of electrons from metal surfaces on which light shines-emission spectra – emission of light from electronically excited gas atomsWhen solids are heated they emit radiation (red glow on electric stove)Wavelength distribution of radiation depends on temperatureQuantum  means fixed amount-Smallest quantity of energy that can be emitted or absorbed as electromagnetic radiationE=hvh = planck’s constant  6.626 X 10^-34 J-sphoton – packet of energywork function = amount of energy require for the electrons to overcome the attractive forces holding them in the metal spectrum : dispersion of radiation into its component wavelengthscontinuous spectrum: if spectrum contains all wavelengthsline spectrum : contains only specific wavelengths Bohr’s model postulates:-only orbits of certain radii, corresponding to certain specific energies, are permitted for the electron in a hydrogen atom-an electron in a permitted orbit is in a “allowed” energy state. An electron in an allowed energy state does not radiate energy and, therefore, does not spiral into the nucleus-energy is emitted or absorbed by the electron only as the electron changes from one allowed energy state to another. This energy is emitted or absorbed as a photon that has energy E=hvground state  lowest energy stateexcited state  electron is in higher energy stateelectron must absorb energy to move to higher-energy statewavelength and frequency are always reported as