Procedure

The full procedure is available within the Capstone workbook in the lab, so here we provide a brief overview of what you will be doing in this experiment, as well as a breakdown of what will be marked. Note, there are no individual lab reports required for this lab. All data submissions and answers to questions will be handed in as one group digital submission. There are no sample calculations required for this lab either.

Figure 5 shows a labelled photo of the apparatus used to measure the data you will be analyzing in this experiment. There is a video on Avenue “Apparatus introduction” which provides a description of each part of the apparatus. You may compare these to Figures 1, 3, 4, and 5 to get familiar with how light passes through the grating to create the spectral lines, and how the apparatus will measure the light.

In this experiment you will analyze the different colours of the spectra emitted by helium, hydrogen, and one mystery gas measured with the grating spectrophotometer. From the resulting graphs, you will determine the wavelengths of the spectral lines by measuring the angle from the central maximum to each line. Only lines will be examined. The spectrum of helium will be used to calibrate the diffraction grating. Then you will compare your estimated wavelengths of the spectral lines to the accepted values. In the case of hydrogen, you will identify the electron orbit transitions corresponding to the observed lines. Finally, you will match the spectrum of an unknown gas to template spectra to identify the emitting substance.

Calibration, grating spacing: 0.75 marks

He spectrum figure and table: 1.75 marks

Spectral line width measurement: 0.75 marks

Question 1: 0.5 marks

H spectrum figure and table: 1.75 marks

H energy levels table: 0.5 marks

Mystery spectrum figure and table: 1.5 marks

Question 2: 1.0 marks

Question 3: 1.0 marks

Question 4: 0.5 marks

Saving your Capstone workbook

Here we discuss how and where to store the results from your Capstone workbook for marking. If any of the following instructions are unclear, be sure to double-check that you are doing this correctly with your TA.

To save your work, we will make use of the “snapshot” feature in the Capstone software.

A snapshot of each page can be recorded with the following steps:

• Click the dropdown arrow next to the camera button near the top of the screen.
• Make sure the “Snapshot Workbook Page Content” option is selected.
• Click the camera button. This will take a snapshot of the current workbook page.

The yellow button to the right of the camera button that looks like a book will display the “Journal,” which is an area within the Capstone software that stores the snapshots as they are taken. This button merely toggles the display of the journal within the software window. All snapshots will be stored to the journal whether this button is active or not. Be sure to check the Journal to ensure you have taken a snapshot of every page of your workbook. Note: This includes the page with your names and student numbers! If you would like to delete a snapshot, you can do so by clicking on the snapshot, then clicking on the red “x” button at the top of the journal window.

When your journal is complete, you are ready to export your snapshots. Export your Journal by finding the icon in the Journal window near the top that looks like a folder with a small arrow pointing to it. If you hover the mouse cursor over the icon but don’t click, it should say “Export to HTML”. Click this button, and be patient if nothing happens immediately–sometimes this action takes several moments. When the software is ready, a File Explorer window will open on the screen, and you will be asked to select a folder to export the Journal to. Navigate to the Desktop, enter the folder that corresponds to your Lab section, and then the workstation number that you are at. Once you have successfully exported your Journal, the File Explorer window will close.

Finally, before you leave the lab, find your exported Journal by opening a new File Explorer window and navigating into the folder/directory that you exported to. You should see a folder with the name of the experiment–specifically, the name of the Capstone software file. Within this folder should be one HTML file and a series of PNG images, one for each of your Capstone workbooks. These images will make up the digital portion of your lab submission. Double check with your TA that your snapshots have been taken properly before you leave.