A vapor light also produces visible light by electroluminescence The bulb contains a small amount of solid sodium or mercury as well as a mixture of neon and argon gases. When an electric current passes through the gases, it causes the solid sodium or mercury to change to a gas and emit visible light. Sodium vapor lights, like the streetlight pictured in the Figure below , produce yellowish light. Mercury vapor lights produce bluish light. In addition to lighting city streets, vapor lights are used to light highways and stadiums. The bulbs are very bright and long lasting so they are a good choice for these places.
The high school wanted to play night games for football and baseball. After some discussion the school board decided that they needed a type of light that was bright and long lasting. Sodium vapor and mercury vapor lights where the two final choices and they decided to vote fo9r the final choice.
Which lights are bright and long lasting?