H2+H4

The equation you've provided, H2 + H4, seems to be an addition of two hydrogen-related molecules. However, you might be referring to a chemical reaction or a combination of hydrogen molecules.

It's important to note that under standard conditions, hydrogen gas exists primarily as H₂ (diatomic hydrogen). H₄ does not represent a stable or common molecular form of hydrogen; the stable forms of hydrogen gas are H₂ (most common) and H (atomic hydrogen).

Could you clarify if you're asking about a specific reaction or provide more context?