Atomic Structure I

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Slide 1

Atomic Structure

It’s not about Dalton anymore…

Slide 2

First…

To understand the electronic structure of the atom we need to review the properties of electromagnetic radiation.

Slide 3

Figure 7.1

Frequency and Wavelength

c = l n

l = wavelength

n = frequency

C = speed of light

The Wave Nature

of Light

Slide 4

The waveheight or amplitude determines radiation intensity.

The wavelength is related to the energy of the radiation.

Slide 5

λ, ν, and Energy

As λ decreases and ν increases, what happened to the energy of the radiation?

where h = Planck’s constant

(6.626 × 10-34 m2 kg/s)

Slide 6

Regions of the electromagnetic spectrum.

The infinite number of wavelengths of

electromagnetic radiation have been classified

into groups as shown below.

Slide 7

SOLUTION:

Interconverting Wavelength and Frequency

Use c = ln

= 1.00x10-10 m

= 325x10-2 m

= 473x10-9 m

n =

3x108 m/s

1.00x10-10 m

= 3x1018 s-1

n =

n =

3x108 m/s

325x10-2 m

= 9.23x107 s-1

= 6.34x1014 s-1

Slide 8

SOLUTION:

Calculating the Energy of Radiation from Its Wavelength

After converting cm to m, we can use the energy equation, E = hn combined with n = c/l to find the energy.

E = hc/l

E =

6.626X10-34J*s

3x108m/s

1.20cm

x

= 1.66x10-23J

Slide 9

Particle or Wave?

Different behaviors of waves and particles.

Slide 10

The diffraction pattern caused by light

passing through two adjacent slits.

Slide 11

Light is a wave…right?

Light falling on alkali metals causes electrons to be released from the metal.

The # of electrons depends on the intensity of light.

There are specific wavelengths of light that cause the release of e-.

This is called the photoelectric effect.

Slide 12