Embedded Files
This lab will go in your lab book. Follow the directions below to complete the lab.
Purpose (put into lab book)
The purpose of this lab is to observe the spectra of various elements.
Background (summarize and put into lab book)
Ground State - Electrons sit in the lowest energy levels, as close to the nucleus as possible. This is the normal electron configuration that we have been writing.
Lithium's electron configuration is shown to the right. A picture of lithium is also shown. The blue circle represents the nucleus and the red dots represent the electrons. There are two electrons in the first energy level (the first ring) and there is one electron in the second energy level (the second ring). This is the normal placement for the electrons in lithium so it is called the ground state.
Excited State - Electrons move to a higher energy level due to energy being added.
The diagram to the right is still lithium. Energy was added. The electron that was on the second energy level was moved to a higher energy level. This is represented by the old place the electron was located is in grey, the arrow shows the addition of energy, and the red is the new placement of the electron. The more energy that is added, the further the electron would travel.
The electron does not stay in this higher energy level for long. It drops back down to the ground state. When it moves back to the ground state energy is released in the form of light.
The glass tubes that we are examining are filled with elements in the gas phase.
The glass tube is placed into a black box so that electricity can run through the gas.
The electricity adds energy to the electrons causing the excited state.
Procedure (put in lab book)
Turn on the light.
Record the color that the gas glows in the bulb (remember this is due to the excited electrons).
Look through the diffraction grating to view the elements spectra (this splits the colors into a pattern of lights called the spectra).
This pattern can be seen on the left and right of the light, it is just mirror images.
Draw the pattern of lights (the spectra) that you see as accurately as possible. Your picture should include the gas bulb (in the correct color), the spectra viewed on the left, and the spectra viewed on the right.
Data (the data table in your lab book needs a column for the element and for the picture of spectra that you draw)
Element
Spectra Viewed
Your picture of the spectra
Subatomic Particles
(give how many protons, neutrons, and electrons that element has)
Electron Configuration (give the full or noble gas electron configuration, except for Hg)
[Ar]4s23d104p6
Outer Electrons
The bulb is in the middle. The spectra is located on both the left and right. Remember they are mirror images of each other.
(Including the bulb and the spectra on both sides of the bulb)
Krypton
36 p+
48 n
36 e-
This one we did together as a class so you would understand how to draw it properly. Examine the viewed spectra and the the picture so you can see how to do it in your lab book.
8
Hydrogen
Helium
Neon
Mercury
----------------
Argon
Conclusion (answer the following questions in your lab book - NO 3 PARAGRAPH CONCLUSION)
What is happening to create the spectra you are seeing?
Does every element have the same spectra?
Why do you think this is the case?
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