# How did Halogens become known as Halogens? They are not the only elements that form salts!

Having never given it a though before, I recently discovered (in a different context) that the prefix halo- actually means 'salt' or 'sea' and the suffix -gen means 'to form' or 'to generate'. So the Halogens are the elements that 'form salts'. But there are salts that do not have halogens in them, like $\ce{Na2S}$ or $\ce{(NH4)2SO4}$. Was it known at the time that other salts existed, and what other names for this group might have been considered?

On a side note, why aren't Group I metals called halogens? Doesn't it take two to tango (I mean, to form salts?)