Which one among the following statements for the gases mentioned below

Which one among the following statements for the gases mentioned below is not correct ?

Hydrogen has 3 isotopes.
Helium is a commonly used gas in electric bulbs.
Oxygen is used to burn fuel in rocket engines in spacecraft.
Nitrogen can be used in gaseous form to replace air in food packaging.
This question was previously asked in
UPSC CDS-2 – 2024
Statement B, “Helium is a commonly used gas in electric bulbs,” is not correct.
Standard incandescent electric bulbs commonly use inert gases like Argon or Nitrogen to reduce filament evaporation and blackening of the bulb. While Helium can be used in some specialized discharge lamps or gas mixtures, it is not the gas commonly found in typical household electric bulbs.
Statement A is correct: Hydrogen has three common isotopes: Protium (¹H), Deuterium (²H), and Tritium (³H). Statement C is correct: Oxygen (or an oxidizer like Liquid Oxygen, LOX) is essential for burning fuel in rocket engines through combustion. Statement D is correct: Nitrogen is an inert gas used in Modified Atmosphere Packaging (MAP) for food to displace oxygen, preventing oxidation and inhibiting the growth of aerobic bacteria, thus extending shelf life.