CHEM 370 | Week 6

layout: true

.footer[
- <div class="tooltip"><a href="/"><i class="fas fa-home"></i></a> <span class="tooltiptext">Go to C370 Main Page</span></div>
- <div class="tooltip"><a href="/lecture-slides"><i class="fas fa-chalkboard-teacher"></i></a><span class="tooltiptext">Go to Lecture List</span></div>
- <div class="tooltip"><i class="fas fa-question"></i><span class="tooltiptext">Press <kbd>Shift</Kbd> + <kbd>?</kbd> for Navigation Tips!</span></div>
]

---
class: center

<div style="margin-top: 100px;"></div>
<h1 style = "text-align: left; font-weight: bold; margin-left: 175px;">Week 6: Spectroscopy Intro</h1>
<h5 style = "text-align: left; font-weight: bold; margin-left: 175px;">Harvey Chs 10</h5>
<img src="https://upload.wikimedia.org/wikipedia/commons/f/f5/Light_dispersion_conceptual_waves.gif" style = "height:250px; margin-left: auto; margin-right: auto; display: block;">

---

# Spectroscopy

> **Spectroscopy** is the study of the interaction of *light* and *matter*.

.image-credit[[Philip Ronan, Gringer](https://commons.wikimedia.org/wiki/File:EM_spectrumrevised.png) / [CC BY-SA](https://creativecommons.org/licenses/by-sa/3.0)]

---

# Light as a Wave

![A representation of plane-polarized light showing the perpendicular electric and magnetic fields propagating through space.](https://upload.wikimedia.org/wikipedia/commons/3/35/Onde_electromagnetique.svg)

.image-credit[[Onde electromagnetique by SuperManu, via Wikimedia.org](https://commons.wikimedia.org/wiki/File:Onde_electromagnetique.svg) [CC-BY-SA 3.0](http://creativecommons.org/licenses/by-sa/3.0/)]

---

# Electromagnetic Spectrum

.image-credit[David Harvey / [Analytical Chemistry 2.1](https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Book%3A_Analytical_Chemistry_2.1_%28Harvey%29) / [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/3.0/at/deed.en)]

---

# Example: Sodium

> In 1817, Josef Fraunhofer studied the spectrum of solar radiation, observing a continuous spectrum with numerous dark lines. Fraunhofer labeled the most prominent of the dark lines with letters. In 1859, Gustav Kirchhoff showed that the D line in the sun’s spectrum was due to the absorption of solar radiation by sodium atoms. The wavelength of the sodium D line is 589 nm. What are the frequency and the wavenumber for this line?  What is the energy of a photon with $\lambda$ = 589 nm?

![An 1-D electromagnetic spectrum of the visible region with wavelength on the horizontal axis, colored to match typically perceived colors.  Fraunhofer lines are overlaid as dark bars.](https://upload.wikimedia.org/wikipedia/commons/2/2f/Fraunhofer_lines.svg)

.image-credit[Public Domain Image, via [Wikimedia](https://commons.wikimedia.org/wiki/File:Fraunhofer_lines.svg)]