Here's why:

* Atomic Structure: Hydrogen has only one proton and one electron.

* Octet Rule: Atoms tend to gain, lose, or share electrons to achieve a stable configuration with eight electrons in their outermost shell (except for hydrogen and helium, which only need two electrons).

* Hydrogen's Behavior: Hydrogen can either lose its single electron, forming a +1 ion (H+), or share its electron with another atom to form a covalent bond.

Therefore, hydrogen typically exhibits a valence of +1, indicating its tendency to lose one electron.