Identify the elements present in the orginal compound using the following statement of a chemical reaction.?
a white solid is heated and gives off carbon dioxide, co2 and water, h2o, leaving behind soduim carbonate, na2co3.

Ido not understand. 

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   

Idon't know hope someone you

Go ask spider man