Which of these is a heavy gas used in specialized electric lamps?

Xenon is a heavy gas used in specialized electric lamps. It is commonly used in high-intensity discharge (HID) lamps, such as xenon arc lamps and xenon flash lamps. These lamps produce a bright and intense light, making them suitable for applications like cinema projectors, automotive headlights, and high-speed photography. Xenon gas allows for a more efficient and stable operation of these lamps, resulting in a longer lifespan and better performance compared to other gases.