Spectra Lab

There are three types of light spectra; continuous, absorption, and emission.  In class we did a lab to work on spotting the difference between these three spectra.  We took spectroscopes and looked at different types of light through them.  I took pictures through them with my iPad but they don't look the same as if you'd looked through with your own eyes so I have taken spectra drawings from the Chemistry Cat blog by Nikki Salo because she loves me.

First we looked at a continuous spectra, which is just ordinary light.  There is an orange in that ROY G. BIV down there but you can't really see it because orange is stupid.

Continuous spectra from iPad.

My drawing

Next, containers of colored water were placed in front of the light bulb we were all staring intensely at.  First we looked at red light, then blue light.

The colors are in the far top left corner

This is Nikki's drawing of the visible lights from the red light.

This type of spectra is absorption.  The red light absorbed most of the colors from the continuous emission spectra, mostly the blue and purple colors.

As you can see the iPad didn't quite do the colors justice.

Another of Nikki's drawings because I'm too lazy to draw on an iPad.

The blue light was also an absorption spectra.  This light absorbed the orange colors.  The iPad picture doesn't so that some red was still visible but if you've ever tried to photograph something through a spectroscope you'll understand why the images aren't perfect.

Hydrogen emission picture.

Another of Nikki's masterpieces.

Hydrogen light has an emission spectra.  Only certain colors can be seen through an emission spectra because only certain frequencies of light are emitted.  The lines observed through an emission spectra are spaced and more individual than continuous.

Argon's emission spectra through the iPad

Nikki's version of Argon's emission spectra.

Argon has a different emission than Hydrogen.  All atoms have different, characteristic emission spectra.

Mercury emission.

Inspiring artwork.

Mercury vapor was pretty to look at.  Lights are pretty.  It was the same color as a bug zapper...  The iPad picture does a very poor job of showing the emission spectra of mercury but thankfully Nikki's picture makes up for it.

Nitrogen from an iPad's perspective.

I want emission spectra on a T-shirt.

So here we have Nitrogen's emission spectrum!  The iPad picture for this was actually pretty cool.  Perhaps some day cameras will be as amazing and accurate as the human eye and I'll have a much easier time in class.  One can dream!

Helium emission!

Nikki's drawing of said emission.

The lines on helium's spectrum was a lot cooler than the iPad says it was but it still looks shiny.  Nikki's drawing will, as usual, provide a more accurate example of the visible colors for helium.

Neon emission according to a lying iPad.

Neon emission from my friend!

The last cathode light we looked at was neon.  The iPad doesn't show near as many lines as we were able to see with our own eyes through spectroscopes.  It was actually kind of intriguing to compare what I could see from my iPad with what I could see for myself.  Oh technology, you lying inconvenient thing!
And there we have it!  The three spectra!  Continuous spectra, which is a really pretty rainbow, like the kinds the prism in my car throws; absorption spectra, which is when some colors aren't visible because they've been absorbed by the colored light; and emission spectra, the fun way to characterize elements!
I remember doing this lab freshman year.  Only back then we used these things called colored pencils.  You take this 'colored pencil' and you scribble with it on something known as 'paper'.  It's kind of like Doodle Buddy only instead of your finger, you have a stick.