Lets say a giant radioactive monster is attacking Phoenix. This monster is so radioactive and big the air in
Feels easily over 120°. Is this an endothermic or
exothermic reaction?

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