Question

Is hydrogen gas flammable?

Answer 1

Explanation:

Hydrogen has the highest flammability rating $4$ because it is flammable even when combined with small amounts of normal air, combustion will reduce the hydrogen to air volumetric ratio by up to $4\%$ due to oxygen in the air, and the reaction's simplicity and chemical properties.

1. It is the lightest gas and is explosive in air, at concentrations exceeding about $4\%$($\mathrm{Lewis}1996$).
2. When hydrogen comes into contact with oxygen, chlorine, or other oxidizers, it becomes flammable and unstable, and it burns with an almost imperceptible flame.

Hence, hydrogen gas is flammable.