Okay kiddo, think of an atom like a puzzle piece. The puzzle piece has its own shape and size, and it has electrical charges inside called electrons and protons.
Now, when two puzzle pieces come together, they can make a bigger piece or molecule. In this case, we're talking about two hydrogen atoms coming together to make a hydrogen molecule.
But sometimes, we only have one hydrogen atom with only one electron and one proton. This is called a hydrogen ion.
Now, if we take that hydrogen ion and add another hydrogen ion to it, we get something called a hydrogen molecular ion. It's like combining two half-puzzle pieces to make a whole one.
The hydrogen molecular ion has two protons and only one electron. This means it has a positive charge because there's an extra proton compared to the number of electrons.
Scientists study hydrogen molecular ions to understand how they react with other molecules and how they can be used in different chemical reactions. It may sound small, but it can help us understand big things like how stars and planets form.