Question

The colour of the red glass in traffic signals is due to:

• A. $S{b}_2{S}_3$
• B. $Hg{I}_2$
• C. $CdS$
• D. $CdSe$

Answer 1

The correct option is D $CdSe$

The colour of the red glass in traffic signals is due to cadmium selenide or $CdSe$.
Red glass can also be obtained by adding trace amount of gold and copper.