I was wondering what compounds are used to make red, amber, and green colored glass in old traffic lights. Google was no help at all. This is for an assignment due really soon, so if anyone knows, tell me.

Copper gives green glass, gold gives red, silver gives yellow. look for 'stained glass' in google, rather than 'traffic lights'.

Barium salts (Chlorate) are used for Green.

Sodium is used for Yellow.

and Strontium is used for Red.

 

Copper salts are used for Blue

 

edit: Oooops, just realised, it was a Gl;ass thingy and not a Pyro one (we have traffic lights in those too).

 

Chromium salts give the yellow

copper for the green

 

I`m not too sure about the red?

 

cobalt gives Blue.

Cadmium Sulfide and traces of Selenium added to molten glass gives it a red color when it sets.

CdS

 

also used in PhotoCells, slow reactions, but good stuff

Cadmium Sulfide and traces of Selenium added to molten glass gives it a red color when it sets.

 

Old traffic lights, as in 'not new'.

 

 

The first traffic lights were installed in 1868, and most probably used the old methods for colouring : -

http://www.thestorefinder.com/glass/library/history.html

Thanks. I'm actually going to pass.