the ammonium is a polyatomic ion that consists of one nitrogen atom bonded to four hydrogen atoms. The ammonium ion has a single positive charge on it. Draw the Lewis structure of the ammonium ion.

Maybe you should get some from your teacher and learn more so you can get your grades up and maybe study a bit more

While unproven, it uses facts to support part of a conclusion. it is still factual and has predictive power, however.

Ch4 and ph3 are both covalent since they are composed both of non-metals.    ch4 is non- polar because of  london forces and has a geometry of tetrahedral  ph3 , on the other hand, is umbrella shaped polar and has dipole-dipole intermolecular force (imf) . since ph3 is polar, it has a stronger imf   

I'm sorry but i'm only grade