Consider the following oxide Na2O ZnO Al2O3 Co2,H2o
​

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   

The percentage of the rock record is 66%plz mark me brainliest! hope this !

Number of molecules=(12.01+2x15.9994)/112 x na