1. I’m coming around to grade this.

2. Understand the electromagnetic spectrum and how it is organized.
Understand what different types of electromagnetic radiation can reveal about astronomical objects.
Understand and describe important properties of electromagnetic radiation.
Understand how technology is used to collect electromagnetic radiation and turn it into images.
Understand what can be learned from analyzing the light from astronomical objects.
Understand how different types of lenses and telescopes work
Understand and describe the quantization of energy at the atomic level
Understand that all objects emit and absorb electromagnetic radiation and distinguish between objects that are blackbody radiators and those that are
Qualitatively describe the shift in frequency in sound or electromagnetic waves due to the relative motion of a source or a receiver

3. Finally
Spectrum Analysis

4. A B C D E F G Ar H He Hg I Kr Ne
Sunlight/
Candle

5. Today’s Question
What can we learn by observing the light (spectrum) of an object?

6. read. answer.
It is online if you want it in color

7. 3 types of spectra Continuous Emission (bright line)
Absorption (dark line)

8. Type
Information
Sketch
Continuous
Emission
Absorption

9. 3 types of spectra – sketch them
Continuous
Emission (bright line)
Absorption (dark line)

11. Continuous spectra
Continuous spectra are emitted by any object that radiates heat (has a temperature).
The light is spread out into a continuous band with every wavelength having some amount of radiation. For example, when sunlight is passed through a prism, its light is spread out into its colors.

12. Emission spectra
emission spectra occur when the atoms and molecules in a hot gas emit extra light at certain wavelengths, causing bright lines to appear in a spectra.
Like absorption spectra, the pattern of these lines are unique for each element, similar to a fingerprint. We can see emission spectra from comets, nebula and certain types of stars.

13. This is why you saw those lines in the lab.
extra light at certain wavelengths, causing bright lines to appear in a spectra.

14. Emission Spectra
This is also why different elements will burn with different colors
barium a green flame
lithium and strontium a red flame
calcium an orange flame
sodium a yellow flame
copper a blue flame

15. Absorption and Emission Spectrums are inverses of each other

16. Absorption spectra
the pattern of dark lines or bands that occurs when light is passed through an absorbing medium into a spectroscope
The pattern of these lines is unique to each element and tells us what elements make up the atmosphere of the object. We usually see absorption spectra from regions in space where a cooler gas lies between us and a hotter source.
We see absorption spectra from stars, planets with atmospheres, and galaxies.

17. All the Colors of the Sun
If you look more closely at the Sun's spectrum, you will notice the presence of dark lines.
These lines are caused by the Sun's atmosphere absorbing light at certain wavelengths, causing the intensity of the light at this wavelength to drop and appear dark. The atoms and molecules in a gas will absorb only certain wavelengths of light.

20. Why is this happening? Because Light.
Light is a wave.
Light is a particle.

21. Light
Light is created when an electron moves from a higher energy level to a lower energy level.
The photon (or particle of light) emitted has an energy that corresponds exactly to the difference in energy between the two levels.

22. Chemical Fingerprints
Because all elements have different atomic structures the electrons around the nucleus emit photons at frequencies that are very characteristic of that particular atom
The bright line and dark line (emission and absorption) spectrum is a chemical fingerprint for the element in question.

23. Emission Spectra of every element

24. atoms can absorb and emit packets/particles/photons of electromagnetic radiation.
the light has discrete energy dictated by the detailed atomic structure of the atoms
everything in nature strives to be at its most stable, lowest-energy state, so “excited” or energized electrons will move back down toward their stable shell in small jumps.

25. Online activity

26. solar spectrum with fraunhofer lines as it appears visually

31. Mystery Star

32. Mystery Star

33. Mystery Star

34. Mystery Star

36. Please go back and answer today’s (and Tue. and Wed. question
What can we learn by observing the light (spectrum) of an object?

37. Homework…Read each tab, and then do the exercises on the 4th tab
Homework…Read each tab, and then do the exercises on the 4th tab. There will be a test question or two taken directly from this activity….