Quantum Theory of the Atom

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Slide 1

Quantum Theory of the Atom

7.1 The Wave Nature of Light

7.2 Quantum Effects and Photons

7.3 The Bohr Theory of the Hydrogen Atom

Slide 2

The Wave Nature of Light

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Presentation of Lecture Outlines, 7–2

A wave is a continuously repeating change or oscillation in matter or in a physical field. Light is also a wave.

It consists of oscillations in electric and magnetic fields that travel through space.Visible light, X rays, and radio waves are all forms of electromagnetic radiation.

Slide 3

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Presentation of Lecture Outlines, 7–3

The Wave Nature of Light

A wave can be characterized by its wavelength and frequency.

The wavelength, l (lambda), is the distance between any two adjacent identical points of a wave. The frequency, n (nyu), of a wave is the number of wavelengths that pass a fixed point in one second.

Slide 4

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Presentation of Lecture Outlines, 7–4

So, given the frequency of light, its wavelength can be calculated, or vice versa.

The Wave Nature of Light

The product of the frequency, n (waves/sec) and the wavelength, l (m/wave) would give the speed of the wave in m/s.

Slide 5

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Presentation of Lecture Outlines, 7–5

If c = nl, then rearranging, we obtain l = c/n

The Wave Nature of Light

What is the wavelength of yellow light with a frequency of 5.09 x 1014 s-1?

(Note: s-1, commonly referred to as Hertz (Hz) is defined as “cycles or waves per second”.)

Slide 6

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Presentation of Lecture Outlines, 7–6

Figure 7.5: The electromagnetic spectrum.

Slide 7

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Presentation of Lecture Outlines, 7–7

If c = nl, then rearranging, we obtain n = c/l.

What is the frequency of violet light with a wavelength of 408 nm?

The Wave Nature of Light

Slide 8

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Seeing the Light-A New Model of the Atom