|Gas in a bulb.
If you look closely you can see the pale green-yellow tint created by the approximately 1 atm pressure of chlorine gas in this sealed bulb. There's a very similar bulb under bromine, but its color is much, much darker. Normally when you see a "gas" that is colored, it's not really a gas but rather tiny droplets of liquid (in fog) or particles (in smoke) that make it look colored or thick. The difference is that in a real colored gas, there is no diffusion of the light, just attenuation. A fog or smoke makes things look fuzzy, while with a true colored gas, they look perfectly sharp, just colored.
I received this sample when Tryggvi and Timothy came to my sodium party.
I chose this sample to represent its element in my Photographic Periodic Table Poster. The sample photograph includes text exactly as it appears in the poster, which you are encouraged to buy a copy of.
Source: Tryggvi Emilsson and Timothy Brumleve
Contributor: Tryggvi Emilsson and Timothy Brumleve
Acquired: 21 September, 2002
Text Updated: 4 May, 2007