Task: Question Generation
Input (English): Background Paragraph: 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. 
Story: Joey just purchased two new vapor light bulbs for his apartment and is excited to install them since they glow neat colors. He is going to install a different bulb in each room to give different colored glows to the rooms and to make his apartment seem more dynamic. In his bedroom he has decided to install a bulb that gives off a blue glow. He also picked up a bulb that glows yellow and will be putting that in his closet. However, after screwing the bulbs in, only the one in his closet glows, and Joey is not sure why.
Output (English): Is the bulb in the closet or bedroom filled with sodium?