Here's why:

* Hydrogen has one proton and one electron. Protons have a +1 charge, and electrons have a -1 charge.

* To become stable, hydrogen tends to lose its one electron. This leaves it with one proton and no electrons, resulting in a net charge of +1.

It's important to note that hydrogen can also form a -1 ionic charge in some cases, like when it bonds with a more electronegative element. However, the +1 charge is the more common and stable state.