Modern Chemistry Chapter 4 Arrangement of Electrons in Atoms Sections 1-3 The Development of a New Atomic Model The Quantum Model of the Atom Electron Configurations
The Development of a New Atomic Model Section 1 The Development of a New Atomic Model Chapter 4 Section 1 New Atomic Model pages 97-103
Chapter 4 Section 1 New Atomic Model pages 97-103 Electromagnetic radiation Electromagnetic spectrum Wavelength Frequency Photoelectric effect Quantum Photon Ground State Excited state Line-emission spectrum Continuous spectrum Section 1 Vocabulary Chapter 4 Section 1 New Atomic Model pages 97-103
Chapter 4 Section 1 New Atomic Model pages 97-103 Properties of Light Electromagnetic Radiation: a form of energy that exhibits wavelike behavior as it travels through space. Wavelength: the distance between corresponding points on adjacent waves Frequency: the number of waves that pass a given point in a specific time. Chapter 4 Section 1 New Atomic Model pages 97-103
Wavelength and Frequency Image p. 98 Chapter 4 Section 1 New Atomic Model pages 97-103
Electromagnetic Spectrum Image Chapter 4 Section 1 New Atomic Model pages 97-103
Electromagnetic Spectrum Image Chapter 4 Section 1 New Atomic Model pages 97-103
Chapter 4 Section 1 New Atomic Model pages 97-103 Properties of Light wavelength x frequency = speed of light x = c Visible Light = R O Y G B I V Long Low Low E Short High High E Chapter 4 Section 1 New Atomic Model pages 97-103
The Photoelectric Effect Max Planck proposed that energy is proportional to the frequency of the electromagnetic wave. Electromagnetic energy is emitted from objects in small packages called quanta. E = h Planck’s constant h = 6.626 x 10-34 J•sec Chapter 4 Section 1 New Atomic Model pages 97-103
Quanitization of Energy Animation Chapter 4 Section 1 New Atomic Model pages 97-103
The Photoelectric Effect Albert Einstein expanded on Planck’s idea. Electromagnetic radiation has a dual wave-particle nature. A particle of light is a photon. Photon: a particle of electromagnetic radiation having zero mass and carrying a quantum of energy. Ephoton = h Chapter 4 Section 1 New Atomic Model pages 97-103
Energy of a Photon Animation Chapter 4 Section 1 New Atomic Model pages 97-103
The Photoelectric Effect The photoelectric effect refers to the emission of electrons from a metal when light shines on the metal. p. 99 Chapter 4 Section 1 New Atomic Model pages 97-103
Photoelectric Effect Animaiton Chapter 4 Section 1 New Atomic Model pages 97-103
The Photoelectric Effect To knock an electron loose, it must be hit with a photon which possesses a minimum amount of energy. This energy corresponds to its frequency. Different metals hold electrons more or less tightly So different metals require different frequencies to show the photoelectric effect. Chapter 4 Section 1 New Atomic Model pages 97-103
The H-Atom’s Line Emission Spectrum Electric current is passed through a vacuum tube with hydrogen in it. A glow is produced When shined through a prism a line emission spectrum is produced p. 101 Chapter 4 Section 1 New Atomic Model pages 97-103
Hydrogen’s Line Emission Spectrum Insert Glencoe Disk 1 Chapter 4 Section 1 New Atomic Model pages 97-103
Absorption and Emission Spectrum Animation Chapter 4 Section 1 New Atomic Model pages 97-103
Line Emission Spectrum Insert Glencoe Disk 1 Chapter 4 Section 1 New Atomic Model pages 97-103
Chapter 4 Section 1 New Atomic Model pages 97-103 Bohr Model of the Atom Niels Bohr proposed orbits for the electrons Each orbit has a fixed energy Lower energy orbits are closer to the nucleus Between orbits the electron cannot exist Chapter 4 Section 1 New Atomic Model pages 97-103
Explaining the Line Emission Spectrum An electron absorbs a specific amount of energy (absorption) and moves from its ground state to an excited state Chapter 4 Section 1 New Atomic Model pages 97-103
Explaining the Line Emission Spectrum The electron returns to its ground state and emits a photon (emission). Chapter 4 Section 1 New Atomic Model pages 97-103
Explaining the Line Emission Spectrum This photon has an energy corresponding to the difference between the two states. This photon has a specific E, , and color. Chapter 4 Section 1 New Atomic Model pages 97-103
Photon Emission and Absorption Image Chapter 4 Section 1 New Atomic Model pages 97-103
Chapter 4 Section 1 New Atomic Model pages 97-103 Bohr Model of the Atom Bohr’s calculated values for the lines agreed with the values observed for the lines in each series. However, it did not explain the spectra of atoms with more than one electron. Chapter 4 Section 1 New Atomic Model pages 97-103
Bohr Model of the Atom Animation Chapter 4 Section 1 New Atomic Model pages 97-103
Chapter 4 Section 1 New Atomic Model pages 97-103 Bohr and Einstein Chapter 4 Section 1 New Atomic Model pages 97-103
Chapter 4 Section 1 New Atomic Model pages 97-103 Section 1 Homework Chapter 4 Section 1 New Atomic Model pages 97-103