Who discovered copper and in what year?

I did a quick google search and it says it's been known since ancient times we don't know what year though. 

The correct answer is "atomic weight".

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