The following compounds will decompose on heating except
A Ag2CO3.
B. CaCO3.
C. K2CO3
D. PbCO.
E. ZnCO3

Where are the questions

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