1. Arrangement of Electrons in Atoms The Development of a New Atomic Model

2. Objectives: 1.Identify the major regions of the electromagnetic spectrum. 2.Explain the mathematical relationship between wavelength, frequency and energy of light. 3.Distinguish between a continuous spectrum and line spectrum. 4.Explain how atoms emit light energy.

3. Rutherford Model of the Atom

5. The Wave Description of Light

7. Wavelength (λ) – the distance between corresponding points on adjacent waves Frequency ( )-the number of waves that pass a given point in a specific time (waves/sec or Hz) Amplitude- the height of a wave measured from baseline to peak or baseline to trough. Speed (c)- distance  time; 3.0 x 10 8 m / s for light traveling in a vacuum. (slightly slower through matter)

8. The Wave Description of Light Wavelength and frequency are inversely proportional

9. The Development of a New Atomic Model Objectives: 1.Explain how line spectra demonstrate the quantized nature of light energy. 2.Describe the Bohr Model of the Hydrogen atom.

11. The Photoelectric Effect the emission of electrons from a metal when light shines on the metal The light must have a minimum frequency depending upon the metal

12. The Photoelectric Effect Max Planck (1900) – suggested that objects emit energy is specific amounts called quanta Quantum- minimum amount of energy that can be lost or gained by an atom E = energy in Joules h = Planck’s constant (6.626 x 10 -34 J*s)  = frequency of radiation emitted

13. The Photoelectric Effect Albert Einstein (1905) – proposed that light could exist as a stream of particles with each particle containing a quantum of energy photon- particle of electromagnetic energy carrying a quantum of energy

14. The Hydrogen Atom Line Emission Spectrum When substances absorb energy, they give of that energy in the form of electromagnetic radiation. ground state – lowest energy state of an atom excited state – a state with higher potential energy

16. Bohr Model of the Hydrogen Atom Niels Bohr (1913) – proposed a model for the H atom to account for the hydrogen line spectrum.

18. Bohr Model of the Hydrogen Atom