What is hydrogen? What does it help? is it dangerous???

Answer 1

Hydrogen is an element, with the smallest sized atom.

It is a key component in water, essential fo life.

Hydrogen by itself is a flammable gas and could explode of not handled corectly.

Answer 2

It is a colourless, odourless, non-metallic, tasteless, highly flammable diatomic gas (two atom combine to form a molecule).
One of the first uses of H2 was for balloons, and later airships. The H2 was obtained by reacting sulphuric acid and metallic iron. Infamously, H2 was used in the Hindenburg airship that was destroyed in a mid-air fire. The highly flammable hydrogen (H2) was later replaced for airships and most balloons by the unreactive helium.
as what you can see from the history incidences, it's dangerous to work with hydrogen, one small spark will cause a deadly explosion.

Answer 3

Hydrogen is the most abundant element in the universe and in earth, it is abundantly available as water. We can't exist without water and carbon based life forms such as proteins etc., and all of them need hydrogen.

Yes, hydrogen can be dangerous if handled carelessly. It forms an explosive mixture with oxygen of air.