why is hydrogen sometimes classed with the group 1 metals in periodic table?

Answer 1

Elements are classed in order of the number of valence electrons they posess. All atoms have electrons in different layers, called "shells". The outer shell is called the "valence level". The number of electrons on the valence level determine how (and to what) the element can bond with other substances. For instance: Hydrogen has 1 valence electron (Hence the Level 1 Class). It can bond with any other element in this class, and with nothing else, since it has but 1 valence electron. Hope this helps!
P.S: I'm 13 years old, best answer please!

Answer 2

It forms a stable ion by losing 1 electron, like the metals in Group 1. But in most other respects, it shouldn't be there.