- Traditional incandescent bulbs often use **Nitrogen** along with a small amount of argon. These gases prevent the filament from oxidizing and help maintain the bulb's lifespan.
- **Halogen** gases, like iodine or bromine, are used in halogen bulbs, not typical incandescent bulbs. These gases allow the filament to run hotter for a brighter light.
- **Carbon Dioxide** is not typically used in bulbs. It's more common in beverages or fire extinguishers.
- **Hydrogen** is not used in bulbs due to its highly flammable nature.

Therefore, your understanding is correct. 🟢 **Option 2: Nitrogen** is the gas used in traditional electric bulbs.

YOUR ANSWER IS RIGHT