Final answer:
When hydrogen is combined with oxygen in the air, it reacts violently and produces a nearly invisible flame.
Step-by-step explanation:
The statement is True. When hydrogen is combined with oxygen in the air, it reacts violently and produces a nearly invisible flame. This reaction is known as combustion and is highly exothermic, releasing a large amount of energy in the form of heat and light. The balanced chemical equation for this reaction is: 2H₂(g) + O₂(g) → 2H₂O(l) +572kJ.