Here's why:

* Hydrogen readily forms bonds with other elements: Hydrogen has only one proton and one electron. This makes it very eager to gain or share an electron to achieve a stable electron configuration.

* Combines explosively with oxygen: Hydrogen readily combines with oxygen to form water (H₂O). This reaction is highly exothermic and can occur explosively under certain conditions.

* Forms compounds with many other elements: Hydrogen is a component of many common compounds, including hydrocarbons (like methane and propane), acids (like sulfuric acid), and even water.

While hydrogen is flammable and explosive, it is also the most abundant element in the universe and plays a crucial role in many chemical reactions.