1. Spectra Lab

2. Spectra Lab
Purpose: We will observe and draw the three different types of spectra.
Materials: Spectroscopes
Light sources
Colored pencils/crayons

3. Research
Vocab:
spec·trum (ˈspektrəm/ noun)-1. a band of colors, as seen in a rainbow, produced by separation of the components of light by their different degrees of refraction according to wavelength.
2. the entire range of wavelengths of electromagnetic radiation.
in·can·des·cent (ˌinkənˈdes(ə)nt)light- emitting light as a result of being heated.
fluo·res·cent (ˌflo͝o(ə)ˈresənt,flôrˈesənt) light- absorbing light of short wavelength and emitting light of longer wavelength.

4. Spectroscope Diagram A spectroscope works by:
Using a spectroscope will separate light into its corresponding spectra.
A spectroscope works by:
Allowing a source of light to enter a narrow, slit-like opening
Having it pass through a prism or diffraction grating
And the result projected onto a screen for viewing.
Narrow opening
Prism
Light source
Screen

5. Kirchhoff's 3 Laws of Producing Spectra
Research
Kirchhoff's 3 Laws of Producing Spectra

6. Kirchhoff's Laws Research
Continuous Spectrum
First Law: A hot solid, liquid, or dense gas emits radiation at all wavelengths ("a continuous spectrum of radiation").

7. Kirchhoff's Laws Research Emission Spectrum
Second Law: A low density hot gas in front of a cooler background emits radiation at a discrete set of isolated wavelengths.
These discrete, isolated wavelengths are called the "emission lines" of the spectrum. The whole spectrum is called an "emission-line" spectrum.
The wavelengths of the emission lines are unique to the type of atom that is producing the emission lines.
2 types of emission spectra

8. Kirchhoff's Laws Research Absorption Spectrum
Third Law: A thin cool gas in front of a hotter solid, liquid, or dense-gas background removes the radiation from the background source at special wave lengths.
The spectrum is dark lines superimposed on the continuous band of colors due to the background. These dark lines are called "absorption lines.“
The wavelengths of the absorption lines are unique to the type of atom that is producing the emission lines.

9. Absorption and Emission Lines
Research
Absorption and Emission Lines
If a certain type of gas produces absorption lines at certain wavelengths when it is in front of a hot background, then when that same type of gas is seen in front of a cooler background, it produces emission lines at the exact same wavelengths.

10. Cool
Hot
Star
Star
1st Law
3rd Law
2nd Law

11. 1st Law- Continuous
2nd Law- Emission
3rd Law- Absorption

12. Procedure
Procedure: Using the spectroscopes, observe and draw the different spectra. Use colored pencils or crayons to color your spectra correctly. Label 2 things:
The type of spectrum it is (Continuous, Emission, Absorption)
Which of Kirschhoff’s laws is shown (1st, 2nd , or 3rd Law)